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  • 1.
    Alfredsson, Maria
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry.
    Synthesis and Characterization of Acrylfentanyl Metabolites2017Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    Acrylfentanyl is a synthetic opioid that has been widely used in the last year. To help in the fight against synthetic drugs two potential metabolites of acrylfentanyl, one monohydroxy and one dihydroxy were synthesized. These metabolites will hopefully later be implemented in the analytical methods for metabolites of acrylfentanyl in urine by the Swedish National Board of Forensic Medicine.

    To have metabolites for analysis are very important as they are the main target in drug testing.

    The method used to synthesize the metabolites is a five-step synthesis with an additional 6th step for the dihydroxy metabolite. The methods used in the synthesis includes protection of amine with tert-butyloxycarbonyl, reductive amination with sodium triaceto boronhydride, alkylation and demethylation with boron tribromide. The methods used produced good results with high yields in nearly all steps.

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    Synthesis and Characterization of Acrylfentanyl Metabolites
  • 2.
    Alfredsson, Maria
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry.
    Synthesis and characterization of novel thiophene based tetramers for potential detection of protein aggregates2019Independent thesis Advanced level (degree of Master (Two Years)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    Alzheimer’s disease is a big problem in the elderly population. An important tool in gaining insight in this disease are staining studies using different probes. Conjugated oligothiophenes have shown promising properties as probes and in this thesis new potential probes have been made.

    Three new tetrameric probes have been synthesized, consisting of three thiophene units and one aromatic heterocycle moiety. The aromatic heterocycles used were BTD, pyridine and indole. The synthesis method involved Suzuki cross coupling, bromination with NBS and iridium catalyst borylation. The BTD and pyridine containing probes were tested in staining experiments and the pyridine probe showed promising results.

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    Report
  • 3.
    Amandusson, Helena
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Hydrogen Extraction with Palladium Based Membranes2000Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Palladium membranes are commercially used to purify hydrogen gas and in dehydrogenation reactions. The combination of the catalytic ability of the membrane surface and the selectivity of hydrogen permeation offers a tool to extract pure hydrogen and to shift a dehydrogenation reaction towards the product side. In this thesis, hydrogen extraction over palladium and palladium-silver based membranes both from different gas mixtures and from dehydrogenated organic molecules is investigated. The aim has been to find the optimal conditions for hydrogen extraction in different environments.

    The hydrogen permeation rate has been shown to depend on both silver concentration on the surface and in the bulk of a palladium based membrane. The diffusion through the membrane is the rate limiting step in the permeation process of most studied membranes. For a palladium membrane with 20 Å silver deposited on the upstream surface, the surface reactions, however, become rate limiting.

    Co-adsorbed oxygen will inhibit hydrogen permeation by blocking hydrogen adsorption sites and by consuming already adsorbed hydrogen in the water forming reaction on Pd membrane surfaces. On Pd70Ag30 membranes, however, oxygen has no effect on the hydrogen permeation rate, mainly due to an effective hydrogen dissolution into silver and a strongly reduced water formation rate. CO blocks hydrogen adsorption sites on both Pd and PdAg membranes effectively below 150°C, but above 300°C, CO has almost no effect on hydrogen permeation.

    Hydrogen can also be extracted through the dehydrogenation of organic molecules. A steady and continuous dehydrogenation of methanol and ethanol, and a subsequent hydrogen permeation, can be maintained in the presence of oxygen through both Pd and PdAg membranes. Without oxygen, a blocking contaminating layer is formed from the decomposition products, which prevents alcohol adsorption and thus also the hydrogen permeation. The hydrogen yield is larger over PdAg membranes than over Pd membranes mainly due to a smaller hydrogen consumption in the water forming reaction, but also due to a larger conversion of the alcohol on PdAg.

    The long time objective of this research has been to develop a method to extract hydrogen from anaerobic bacteria degradation of organic waste material in a co-operation project with microbiologists at the Department of Water and Environmental Studies at Linköping University. The selectivity towards hydrogen permeation in palladium membranes offers a tool to obtain clean hydrogen, which can be used as an energy carrier. By draining the bacteria culture of hydrogen, and thereby reducing the partial pressure of hydrogen, the fermentation process is directed towards a higher production of hydrogen.

    List of papers
    1. Effect of CO and O2 on hydrogen permeation through a palladium membrane
    Open this publication in new window or tab >>Effect of CO and O2 on hydrogen permeation through a palladium membrane
    2000 (English)In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 153, no 4, p. 259-267Article in journal (Refereed) Published
    Abstract [en]

    Hydrogen permeation through a 25-µm thick palladium membrane during continuous exposures of hydrogen together with different combinations of oxygen and carbon monoxide has been studied at membrane temperatures of 100 °C-250 °C (total pressures of 40-150 Torr). Both CO and O2, individually, inhibit hydrogen permeation through the membrane. The cause of the inhibition is, however, somewhat different. CO blocks available hydrogen dissociation sites, while oxygen both blocks dissociation sites and also consumes adsorbed hydrogen through the production of water. When a combination of CO and O2 is supplied together with hydrogen, new reaction pathways will emerge. The carbon dioxide formation will dominate the water forming reaction, and consequently, the blocking effect caused by the formation of water will be suppressed. In a mixture of CO+O2+H2, the hydrogen permeation can become either larger or smaller than that due to only O2+H2 or CO+H2 depending on the CO/O2 ratio. It is thus possible to find a situation where carbon monoxide and oxygen react to form CO2 leaving adsorbed hydrogen free to permeate the membrane.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-47729 (URN)10.1016/S0169-4332(99)00357-8 (DOI)
    Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2021-12-01
    2. Hydrogen permeation through surface modified Pd and PdAg membranes
    Open this publication in new window or tab >>Hydrogen permeation through surface modified Pd and PdAg membranes
    2001 (English)In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 193, no 1, p. 35-47Article in journal (Refereed) Published
    Abstract [en]

    The hydrogen permeation through surface modified Pd and Pd70Ag30 membranes has been studied at temperatures between 100 and 350°C. Silver has been evaporated on Pd and Pd70Ag30 foils with a thickness of 25µm in order to study the role of the surface composition in comparison with the membrane bulk composition. The Pd70Ag30-based membranes display the largest permeation rates at temperatures below 200°C, while Pd membranes with 20Å silver evaporated on the upstream side show the largest permeation rates above 200°C. There are, consequently, different rate limiting processes above and below 200°C: at temperatures below 200°C, the bulk diffusion through the membrane is rate limiting, while at temperatures above 200°C, the influence of the surface composition starts to become significant. It has further been concluded that a sharp silver concentration gradient from the surface to the bulk is important for the hydrogen permeation rate at temperatures above 200°C. Adding oxygen to the hydrogen supply will almost totally inhibit the hydrogen permeation rate when a pure Pd membrane surface is facing the upstream side, while for silver-containing surfaces the presence of oxygen has almost no effect. On a clean Pd surface, oxygen effectively consumes adsorbed hydrogen in a water forming reaction. With Ag on the surface, no water formation is detected. Co-supplied CO inhibits the permeation of hydrogen in a similar manner on all studied membrane surfaces, independent of surface silver content. © 2001 Elsevier Science B.V. All rights reserved.

    Keywords
    Hydrogen, Oxygen, Palladium, Permeation, Silver
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-47235 (URN)10.1016/S0376-7388(01)00414-8 (DOI)
    Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2021-12-01
    3. Methanol induced hydrogen permeation through a Pd membrane
    Open this publication in new window or tab >>Methanol induced hydrogen permeation through a Pd membrane
    1999 (English)In: Surface Science, ISSN 0039-6028, E-ISSN 1879-2758, Vol. 442, no 2, p. 199-205Article in journal (Refereed) Published
    Abstract [en]

    The dehydrogenation of methanol and the subsequent permeation of hydrogen through a 25 μm thick palladium film has been studied in a catalytic membrane reactor. At the temperature studied, 350°C, the decomposition pathway for methanol on clean palladium surfaces is believed to lead to Had and a carbonaceous overlayer. The released hydrogen can either desorb or permeate the palladium membrane. During a continuous supply of methanol hydrogen permeation is reduced and, eventually, totally quenched by the growing carbon monoxide/carbon coverage. Adding oxygen in the methanol supply can balance the increasing carbonaceous coverage through the production of carbon dioxide. In such a case, it is concluded that no CO bond scission occurs. The methanol/oxygen ratio is crucial for the hydrogen permeation rate. Isotope-labelled methanol, CH3OH, CH3OD, CD3OH and CD3OD, shows that it is preferentially the methyl (or methoxy) hydrogen that permeates the membrane.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-67400 (URN)10.1016/S0039-6028(99)00892-4 (DOI)
    Available from: 2011-04-11 Created: 2011-04-11 Last updated: 2021-12-01
    4. Isotopic study of ethanol dehydrogenation over a palladium membrane
    Open this publication in new window or tab >>Isotopic study of ethanol dehydrogenation over a palladium membrane
    2000 (English)In: Journal of Catalysis, ISSN 0021-9517, E-ISSN 1090-2694, Vol. 195, no 2, p. 376-382Article in journal (Refereed) Published
    Abstract [en]

    The dehydrogenation of ethanol and the subsequent permeation were studied on a Pd membrane in a continuous ethanol supply. Hydrogen could not be extracted as efficiently from ethanol as from methanol. In ethanol, at least four of the six hydrogen atoms were not available for permeation because of methane formation. Hydrogens bonded to a carbon atom in a C-O group were available for permeation, while hydrogen atoms bonded to a carbon atom without oxygen were not. The efficiency of hydrogen permeation from ethanol was 5% compared to that of pure hydrogen, which could be compared to 25% for methanol compared to pure hydrogen. The hydrogen permeation could be enhanced by adding CO to the EtOH + O2 supply. The permeation probability of the hydrogen bonded to the methylene hydrogen increased while the water formation with this hydrogen atom decreased. Acetic acid was formed upstream when oxygen was in excess. The differently bonded hydrogen atoms in an ethanol molecule experienced different reaction pathways. The results did not contradict the models made from surface experiments in ultrahigh vacuum by Davis and Barteau, Holroyd and Bowker, or Bowker et al.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-47562 (URN)10.1006/jcat.2000.2996 (DOI)
    Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2021-12-01
    5. Alcohol dehydrogenation over Pd versus PdAg membranes
    Open this publication in new window or tab >>Alcohol dehydrogenation over Pd versus PdAg membranes
    2001 (English)In: Applied Catalysis A: General, ISSN 0926-860X, E-ISSN 1873-3875, Vol. 217, no 1-2, p. 157-164Article in journal (Refereed) Published
    Abstract [en]

    The dehydrogenation of methanol and ethanol and the subsequent permeation of hydrogen through Pd and Pd70Ag30 membranes, respectively, have been studied. In order to keep a continuous hydrogen permeation rate, oxygen needs to be added to the alcohol supply. Without oxygen, the decomposition products will form a contaminating layer on the upstream membrane surface. The extraction of hydrogen from ethanol is six times more effective through a Pd70Ag30 membrane than through a pure Pd membrane (at optimum conditions). For methanol, the hydrogen permeation is 30% larger through a Pd70Ag30 membrane than through a membrane of pure Pd. The increased hydrogen permeation yield through Pd70Ag30 compared to Pd can be attributed mainly to a lower upstream consumption of hydrogen due to water formation, but also to an increased conversion of the alcohol in the presence of oxygen. © 2001 Elsevier Science B.V.

    Keywords
    Ethanol, Hydrogen, Membrane, Methanol, Palladium, Silver
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-47269 (URN)10.1016/S0926-860X(01)00591-9 (DOI)
    Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2021-12-01
  • 4.
    Andersson, Anna
    et al.
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Harir, Mourad
    Helmholtz Zentrum München, Germany.
    Gonsior, Michael
    University of Maryland Center for Environmental Science, USA.
    Hertkorn, Norbert
    Helmholtz Zentrum München, Germany.
    Schmitt-Kopplin, Philippe
    Helmholtz Zentrum München, Germany.
    Kylin, Henrik
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Karlsson, Susanne
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Ashiq, Muhammad Jamshaid
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Lavonen, Elin
    Norrvatten, Kvalitet och Utveckling.
    Nilsson, Kerstin
    VA SYD.
    Pettersson, Ämma
    Nodra.
    Stavklint, Helena
    Tekniska verken i Linköping.
    Bastviken, David
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Waterworks-specific composition of drinking water disinfection by-products2019In: Environmental Science: Water Research & Technology, ISSN 2053-1400, E-ISSN 2053-1419, no 5, p. 861-872Article in journal (Refereed)
    Abstract [en]

    Reactions between chemical disinfectants and natural organic matter (NOM) upon drinking water treatment result in formation of potentially harmful disinfection by-products (DBPs). The diversity of DBPs formed is high and a large portion remains unknown. Previous studies have shown that non-volatile DBPs are important, as much of the total toxicity from DBPs has been related to this fraction. To further understand the composition and variation of DBPs associated with this fraction, non-target analysis with ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was employed to detect DBPs at four Swedish waterworks using different types of raw water and treatments. Samples were collected five times covering a full year. A common group of DBPs formed at all four waterworks was detected, suggesting a similar pool of DBP precursors in all raw waters that might be related to phenolic moieties. However, the largest proportion (64–92%) of the assigned chlorinated and brominated molecular formulae were unique, i.e. were solely found in one of the four waterworks. In contrast, the compositional variations of NOM in the raw waters and samples collected prior to chemical disinfection were rather limited.This indicated that waterworks-specific DBPs presumably originated from matrix effects at the point of disinfection, primarily explained by differences in bromide levels, disinfectants (chlorine versus chloramine) and different relative abundances of isomers among the NOM compositions studied. The large variation of observed DBPs in the toxicologically relevant non-volatile fraction indicates that non-targeted monitoring strategies might be valuable to ensure relevant DBP monitoring in the future.

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    Waterworks-specific composition of drinking water disinfection by-products
  • 5.
    Andersson, Kjell
    Linköping University, Department of Physics, Measurement Technology, Biology and Chemistry. Linköping University, The Institute of Technology.
    Development of a Method for Comparing Amphetamine Samples2004Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The studies presented in this thesis were part of a pan-European project, and they describe the research performed to develop a method for comparing amphetamine samples. The work included the following: optimisation of a method for profiling of amphetamine by gaschromatography (GC); optimisation of a technique for preparing samples for GC analysis; testing and evaluation of the abilities of a number of distance metrics to discern links between amphetamine samples originating from the same batch of synthesis analysed using the method developed in the current studies.

    Street amphetamine contains hundreds of different by-products (target compounds), many of which have been identified and found to come from the different conditions used in the manufacturing process. Therefore, the main objective of developing the GC method was to optimise separation and quantification of the target compounds. The best separation was achieved using a DB-35MS capillary column. For quantification, mass spectrometry (MS) in the scan mode employing one target ion seemed to perform best, because this technique provided superior selectivity, and also made it possible to use mass spectra to identify target compounds. In addition, MS detection proved to offer excellent between-laboratory reproducibility.

    The conditions used to prepare amphetamine samples for liquid-liquid extraction (LLE) andsolid-phase extraction (SPE) were also optimised. The sample preparation methods gave similar results but it was easier to use LLE, hence it was chosen for further sample preparation.

    The ability of various numerical methods to find links between amphetamine samples was tested on GC-MS data of 26 target compounds that had been transformed by various pretreatment techniques. The best results were obtained when using Pearson correlation applied to data transformed by normalisation followed by applying fourth root.

    It was also demonstrated that the amphetamine profiling method developed in the current studies was superior to a procedure already in use in a number of forensic laboratories in Europe.

    List of papers
    1. Development of a harmonised method for the profiling of amphetamines: II. Stability of impurities in organic solvents
    Open this publication in new window or tab >>Development of a harmonised method for the profiling of amphetamines: II. Stability of impurities in organic solvents
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    2005 (English)In: Forensic Science International, ISSN 0379-0738, E-ISSN 1872-6283, Vol. 149, no 03-Feb, p. 231-241Article in journal (Refereed) Published
    Abstract [en]

    The present study focused on the stability of 22 amphetamine impurities dissolved in six organic solvents: isooctane, toluene, ethanol, dichloromethane, ethyl acetate, and diethyl ether. The aim was to find the most inert, and thereby most suitable, solvent for amphetamine profiling. Mixtures of the impurities were prepared in the different solvents, and changes in the concentrations of the individual compounds over-time were monitored by gas chromatographic analysis after 0, 4, 12, 24, 48, and 96 h. Isooctane and toluene provided the most inert conditions, although, a few of the impurities were insufficiently stable in these two solvents. The present experiments were performed as a part of the development of a harmonised method for profiling of amphetamine. The results can be used to support the choice of organic solvents for sample preparation. They also provide information about the stability of the impurities that are found in profiles of illicit amphetamine. This is essential due to the fact, that unstable compounds can have a negative influence on the comparison of profiles.

    Place, publisher, year, edition, pages
    Elsevier, 2005
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-72285 (URN)10.1016/j.forsciint.2004.06.019 (DOI)000227862300016 ()
    Available from: 2011-11-24 Created: 2011-11-24 Last updated: 2023-06-21
    2. Development of a harmonised method for the profiling of amphetamines: III. Development of the gas chromatographic method
    Open this publication in new window or tab >>Development of a harmonised method for the profiling of amphetamines: III. Development of the gas chromatographic method
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    2007 (English)In: Forensic Science International, ISSN 0379-0738, E-ISSN 1872-6283, Vol. 169, no 1, p. 50-63Article in journal (Refereed) Published
    Abstract [en]

    This study focused on gas chromatographic analysis of target compounds found in illicit amphetamine synthesised by the Leuckart reaction, reductive amination of benzyl methyl ketone, and the nitrostyrene route. The analytical method was investigated and optimised with respect to introduction of amphetamine samples into the gas chromatograph and separation and detection of the target substances. Sample introduction using split and splitless injection was tested at different injector temperatures, and their ability to transfer the target compounds to the GC column was evaluated using cold on column injection as a reference. Taking the results from both techniques into consideration a temperature of 250 °C was considered to be the best compromise. The most efficient separation was achieved with a DB-35MS capillary column (35% diphenyl 65% dimethyl silicone; 30 m × 0.25 mm, df 0.25 μm) and an oven temperature program that started at 90 °C (1 min) and was increased by 8 °C/min to 300 °C (10 min). Reproducibility, repeatability, linearity, and limits of determination for the flame ionisation detector (FID), nitrogen phosphorous detector (NPD), and mass spectrometry (MS) in scan mode and selected ion monitoring (SIM) mode were evaluated. In addition, selectivity was studied applying FID and MS in both scan and SIM mode. It was found that reproducibility, repeatability, and limits of determination were similar for FID, NPD, and MS in scan mode. Moreover, the linearity was better when applying FID or NPD whereas the selectivity was better when utilising the MS. Finally, the introduction of target compounds to the GC column when applying injection volumes of 0.2 μl, 1 μl, 2 μl, and 4 μl with splitless injection respectively 1 μl with split injection (split ratio, 1:40) were compared. It was demonstrated that splitless injections of 1 μl, 2 μl, and 4 μl could be employed in the developed method, while split injection and splitless injections of 0.2 μl should be avoided.

    Place, publisher, year, edition, pages
    Elsevier, 2007
    Keywords
    Amphetamine; Impurities; Profiling; Optimisation; Separation; Gas chromatography–mass spectrometry
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-72288 (URN)10.1016/j.forsciint.2006.10.018 (DOI)000247113600007 ()
    Available from: 2011-11-24 Created: 2011-11-24 Last updated: 2023-06-21Bibliographically approved
    3. Development of a harmonised method for the profiling of amphetamines: IV. Optimisation of sample preparation
    Open this publication in new window or tab >>Development of a harmonised method for the profiling of amphetamines: IV. Optimisation of sample preparation
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    2007 (English)In: Forensic Science International, ISSN 0379-0738, E-ISSN 1872-6283, Vol. 169, no 1, p. 64-76Article in journal (Refereed) Published
    Abstract [en]

    The suitability of liquid–liquid extraction (LLE) and solid-phase extraction (SPE) for the preparation of impurity extracts intended for gas chromatographic profiling analyses of amphetamine were evaluated. Both techniques were optimised with respect to the extraction of selected target compounds by use of full factorial designs in which the variables affecting the performance were evaluated. Test samples consisted of amphetamine synthesised by the Leuckart reaction, by reductive amination of benzyl methyl ketone and by the nitrostyrene route. The performance of LLE and SPE were comparable in terms of repeatability and recovery of the target compounds. LLE was considered the better choice for the present harmonised amphetamine profiling method due to the lack of information on the long-term stability of SPE columns.

    Place, publisher, year, edition, pages
    Elsevier, 2007
    Keywords
    Amphetamine; Impurities; Profiling; Optimisation; SPE; LLE; GC-FID; GC–MS
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-72289 (URN)10.1016/j.forsciint.2006.10.017 (DOI)000247113600008 ()
    Available from: 2011-11-24 Created: 2011-11-24 Last updated: 2023-06-21
    4. Development of a harmonised method for the profiling of amphetamines V: Determination of the variability of the optimised method
    Open this publication in new window or tab >>Development of a harmonised method for the profiling of amphetamines V: Determination of the variability of the optimised method
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    2007 (English)In: Forensic Science International, ISSN 0379-0738, E-ISSN 1872-6283, Vol. 169, no 1, p. 77-85Article in journal (Refereed) Published
    Abstract [en]

    This paper is the fifth in a series of six in relation to the development of a harmonised method for the profiling of amphetamine [L. Aalberg, K. Andersson, C. Bertler, H. Borén, M.D. Cole, J. Dahlén, Y. Finnon, H. Huizer, K. Jalava, E. Kaa, E. Lock, A. Lopes, A. Poortman-van der Meer, E. Sippola, Development of a harmonised method for the profiling of amphetamines I. Synthesis of standards and compilation of analytical data, Forensic Sci. Int. 149 (2005) 219–229; L. Aalberg, K. Andersson, C. Bertler, M.D. Cole, Y. Finnon, H. Huizer, K. Jalava, E. Kaa, E. Lock, A. Lopes, A. Poortman-van der Meer, E. Sippola, J. Dahlén, Development of a harmonised method for the profiling of amphetamines II. Stability of impurities in organic solvents, Forensic Sci. Int. 149 (2005) 231–241]. The third paper [K. Andersson, K. Jalava, E. Lock, L. Aalberg, Y. Finnon, H. Huizer, E. Kaa, A. Lopes, A. Poortman-van der Meer, M.D. Cole, J. Dahlén, E. Sippola, Development of a harmonised method for the profiling of amphetamines III. Development of the gas chromatographic method, Forensic Sci. Int., in press] dealt with the optimisation of the gas chromatographic and detection methods whereas the fourth paper [K. Andersson, K. Jalava, E. Lock, Y. Finnon, S. Stevenson, L. Aalberg, H. Huizer, E. Kaa, A. Lopes, A. Poortman-van der Meer, M.D. Cole, J. Dahlén, E. Sippola, Development of a harmonised method for the profiling of amphetamines IV. Optimisation of sample preparation, Forensic Sci. Int., in press] concerned the optimisation of the extraction method prior to GC analysis.

    This paper is a study of the optimised method in order to determine its stability. Investigations of within and between day variations were carried out in four laboratories. Moreover, variations between laboratories were also determined. Both flame ionisation detector (FID) and MS detection were used. One laboratory studied nitrogen-phosphorous detector (NPD) detection as well. For this task, 12 batches of amphetamine were prepared. Six of them were synthesised via the Leuckart route, three via the nitrostyrene route and three via the reductive amination route [A.M.A. Verweij, Impurities in illicit drug preparations: amphetamine and methamphetamine, Forensic Sci. Rev. 1 (1989) 2–11].

    Taking into account all studied target compounds and the average results from four laboratories, the within day variation was around 6% for FID and 5% for MS, the between days variation was around 10% for FID and 8% for MS. For NPD detection, within day variation was 5% and between days variation 9% (only one laboratory). Finally, the inter-laboratory variation was about 12% for FID (four laboratories) and 10% for MS (three laboratories).

    Place, publisher, year, edition, pages
    Elsevier, 2007
    Keywords
    Amphetamine; Profiling; GC-FID; GC–MS; GC-NPD; Inter-laboratory variation
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-72290 (URN)10.1016/j.forsciint.2006.10.019 (DOI)000247113600009 ()17178203 (PubMedID)
    Available from: 2011-11-24 Created: 2011-11-24 Last updated: 2023-06-21
    5. Development of a harmonised method for the profiling of amphetamines VI: Evaluation of methods for comparison of amphetamine
    Open this publication in new window or tab >>Development of a harmonised method for the profiling of amphetamines VI: Evaluation of methods for comparison of amphetamine
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    2007 (English)In: Forensic Science International, ISSN 0379-0738, E-ISSN 1872-6283, Vol. 169, no 1, p. 86-99Article in journal (Refereed) Published
    Abstract [en]

    Amphetamine samples were analysed by gas chromatography–mass spectrometry (GC–MS), and the peak areas of 33 target compounds were transformed by applying various pretreatment techniques. The objective was to optimise the ability of a number of distance metrics to establish links between samples of amphetamine originating from the same batch (henceforth refered to as linked distances). Furthermore, partial least squares discriminant analysis (PLS-DA) was used to evaluate the effects of various pretreatment methods on separation of amphetamine batches synthesised by the Leuckart reaction, reductive amination of benzyl methyl ketone, and the nitrostyrene route. The most efficient way to pretreat GC–MS data varied for the different distance metrics, although best results were obtained when data were normalised to the sum of peak areas, and either the fourth root or a logarithm was applied to the normalised data. When pretreating normalised data by fourth root transformation, Pearson correlation was the distance metric that was most successful at finding linked samples. Normalisation and the use of fourth root also represented the best method of pretreating data when employing PLS-DA to separate samples synthesised by different routes. To achieve a faster and more user-friendly procedure for evaluating chromatograms, experiments were performed in which the number of target compounds used to compare samples was reduced. The effect of each compound that was removed was studied by applying PLS-DA and by using Pearson correlation to calculate linked distances as well as unlinked distances (between samples from different batches of amphetamine). Considering both links between samples from the same batch and separation of samples synthesised by different routes, the best results were obtained with the data set comprising 26 compounds. Finally, it was found that the profiling method developed in this work was superior to an existing technique with respect to separating linked and unlinked distances.

    Place, publisher, year, edition, pages
    Elsevier, 2007
    Keywords
    Amphetamine profiling; Numerical methods; Pretreatment; PLS-DA; Pearson correlation; GC–MS; Fourth root
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-72291 (URN)10.1016/j.forsciint.2006.10.020 (DOI)000247113600010 ()
    Available from: 2011-11-24 Created: 2011-11-24 Last updated: 2023-06-21
  • 6. Order onlineBuy this publication >>
    Arja, Katriann
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Multimodal Porphyrin-Based Conjugates: Synthesis and characterization for applications as amyloid ligands, photodynamic therapy agents and chiroptical materials2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Organic compounds that interact both with certain biological targets and display specific photophysical properties can be utilized as molecular tools to visualize and possibly effect disease related processes taking place in living organisms. In this regard, porphyrins are a class of naturally occurring molecules that possess intriguingly interesting photophysical properties where they can act as luminescent probes by emitting detectable light, as well as photosensitizers in the light mediated therapy called photodynamic therapy. In this thesis, the porphyrin structure has been synthetically combined with other molecule classes to achieve compounds with desirable multimodal characteristics.

    Firstly, luminescent conjugated oligothiophenes (LCOs) that have extensively, and with great success, been utilized as fluorescent ligands for amyloid formations, have been conjugated to porphyrins to render oligothiophene porphyrin hybrids (OTPHs) comprising two optically active modalities. When applied as fluorescent amyloidophilic dyes for visualization of amyloid-β (Aβ), one of the pathological hallmarks in Alzheimer’s disease, an enhanced optical assignment of distinct aggregated forms of Aβ was afforded.  Thus, properly functionalized OTPHs could give us more information about pathological processes underlying devastating disorders, such as Alzheimer’s disease. In addition, the OTPHs can be associated with synthetic peptides inducing peptide folding into certain three-dimensional helical structures giving rise to novel optically active materials.

    Secondly, this thesis also embraces porphyrins’ potential as photosensitizers in photodynamic therapy to kill cancer cells. Grounded on the prerequisites for an optimal photosensitizer, we designed porphyrin-based conjugates equipped with common carbohydrates for improved cancer cell selectivity and with a fluorinated glucose derivative, 2-fluoro 2-deoxy glucose, for advantageous metabolism in cancer cells. Furthermore, incorporation of a radioisotopic fluorine-18 atom into the glycoporphyrins could give the means for diagnostic use of the conjugates in positron emission tomography (PET).

    In order to tether together the above-mentioned molecular moieties in a controlled fashion, we developed a robust synthetic strategy for asymmetrical functionalization of porphyrin core. The method involves chlorosulfonation of this otherwise inert tetrapyrrolic structure, followed by alkynylation. Parallelly to amide coupling reactions, copper(I)-catalyzed alkyne azide cycloaddition is used for fast and high-yielding late-stage conjugations. Overall, this thesis demonstrates how combining different molecular moieties in synthetic organic chemistry yields novel molecules with combined and improved multimodal properties for biological and medicinal applications, guided by the design-by-function methodology.      

    List of papers
    1. Enhanced Fluorescent Assignment of Protein Aggregates by an Oligothiophene-Porphyrin-Based Amyloid Ligand
    Open this publication in new window or tab >>Enhanced Fluorescent Assignment of Protein Aggregates by an Oligothiophene-Porphyrin-Based Amyloid Ligand
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    2013 (English)In: Macromolecular rapid communications, ISSN 1022-1336, E-ISSN 1521-3927, Vol. 34, no 9, p. 723-730Article in journal (Refereed) Published
    Abstract [en]

    Fluorescent probes identifying protein aggregates are of great interest, as deposition of aggregated proteins is associated with many devastating diseases. Here, we report that a fluorescent amyloid ligand composed of two distinct molecular moieties, an amyloidophilic pentameric oligothiophene and a porphyrin, can be utilized for spectral and lifetime imaging assessment of recombinant A 1-42 amyloid fibrils and A deposits in brain tissue sections from a transgenic mouse model with Alzheimers disease pathology. The enhanced spectral range and distinct lifetime diversity of this novel oligothiopheneporphyrin-based ligand allow a more precise assessment of heterogeneous amyloid morphology compared with the corresponding oligothiophene dye.

    Place, publisher, year, edition, pages
    Wiley-VCH Verlag, 2013
    Keywords
    oligothiophene, porphyrin, protein deposits, imaging, fluorescence
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-93385 (URN)10.1002/marc.201200817 (DOI)000318354500004 ()
    Note

    Funding Agencies|Swedish Research Council||Knut and Alice Wallenberg Foundation||Swedish Foundation for Strategic Research||European Union FP7 HEALTH (Project LUPAS)||LiU Neuroscience Center||ERC Starting Independent Researcher grant (Project: MUMID)||

    Available from: 2013-05-31 Created: 2013-05-31 Last updated: 2024-01-10
    2. Synthesis and Characterization of Oligothiophene-Porphyrin-Based Molecules That Can Be Utilized for Optical Assignment of Aggregated Amyloid-beta Morphotypes
    Open this publication in new window or tab >>Synthesis and Characterization of Oligothiophene-Porphyrin-Based Molecules That Can Be Utilized for Optical Assignment of Aggregated Amyloid-beta Morphotypes
    2018 (English)In: Frontiers in Chemistry, E-ISSN 2296-2646, Vol. 6, article id 391Article in journal (Refereed) Published
    Abstract [en]

    Molecular tools for fluorescent imaging of protein aggregates are essential for understanding the significance of these pathological hallmarks in proteopathic neurodegenerative diseases, such as Alzheimers disease. Here, we report the synthesis of a series of oligothiophene porphyrin hybrids, OTPHs, and the evaluation of these dyes for fluorescent imaging of beta-amyloid aggregates in tissue sections from a transgenic mouse model with Alzheimers disease pathology. The OTPHs proved to be successful for spectral and lifetime imaging assessment of protein deposits and our findings confirm that the enhanced spectral range and distinct lifetime diversity of these novel tools allow a more precise assessment of heterogeneous amyloid morphology compared with the corresponding oligothiophene dye. In addition, the chemical identity of the porphyrin moiety, as well as the spacing between the two optical active moieties, influenced the OTPHs performance for fluorescent assignment of the protein deposits. We foresee that our findings will aid in the chemical design of dyes that can be utilized as optical tools for studying the polymorphic nature of protein aggregates associated with proteopathic neurodegenerative diseases.

    Place, publisher, year, edition, pages
    FRONTIERS MEDIA SA, 2018
    Keywords
    oligothiophene; porphyrin; protein deposits; imaging; fluorescence
    National Category
    Biophysics
    Identifiers
    urn:nbn:se:liu:diva-151479 (URN)10.3389/fchem.2018.00391 (DOI)000443424100001 ()30234103 (PubMedID)
    Note

    Funding Agencies|Swedish Research Council [621-2013-4754, 2016-00748]

    Available from: 2018-09-24 Created: 2018-09-24 Last updated: 2018-10-19
    3. Synthesis and Characterization of Novel Fluoro-glycosylated Porphyrins that can be Utilized as Theranostic Agents
    Open this publication in new window or tab >>Synthesis and Characterization of Novel Fluoro-glycosylated Porphyrins that can be Utilized as Theranostic Agents
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    2018 (English)In: ChemistryOpen, ISSN 2191-1363, Vol. 7, no 7, p. 495-503Article in journal (Refereed) Published
    Abstract [en]

    Small molecules with modalities for a variety of imaging techniques as well as therapeutic activity are essential, as such molecules render opportunities to simultaneously conduct diagnosis and targeted therapy, so called theranostics. In this regard, glycoporphyrins have proven useful as theranostic agents towards cancer, as well as noncancerous conditions. Herein, the synthesis and characterization of heterobifunctional glycoconjugated porphyrins with two different sugar moieties, a common monosaccharide at three sites, and a 2-fluoro-2-deoxy glucose (FDG) moiety at the fourth site are presented. The fluoro-glycoconjugated porphyrins exhibit properties for multimodal imaging and photodynamic therapy, as well as specificity towards cancer cells. We foresee that our findings might aid in the chemical design of heterobifunctional glycoconjugated porphyrins that could be utilized as theranostic agents.

    Place, publisher, year, edition, pages
    Wiley-VCH Verlagsgesellschaft, 2018
    Keywords
    cancer; glycoporphyrins; imaging; photodynamic therapy; photosensitizers
    National Category
    Medicinal Chemistry
    Identifiers
    urn:nbn:se:liu:diva-150279 (URN)10.1002/open.201800020 (DOI)000440286200002 ()30003003 (PubMedID)2-s2.0-85051290816 (Scopus ID)
    Note

    Funding Agencies|Swedish Foundation for Strategic Research; Swedish Research Council

    Available from: 2018-08-17 Created: 2018-08-17 Last updated: 2019-04-01Bibliographically approved
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    Multimodal Porphyrin-Based Conjugates: Synthesis and characterization for applications as amyloid ligands, photodynamic therapy agents and chiroptical materials
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  • 7.
    Arpa Gonzalez, Enrique Manuel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Bioinformatics. Linköping University, Faculty of Science & Engineering. Univ Autonoma Madrid, Spain.
    Corral, Ines
    Univ Autonoma Madrid, Spain; Univ Autonoma Madrid, Spain.
    Unveiling Photodegradation and Photosensitization Mechanisms of Unconjugated Pterins2023In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 29, no 29, article id e202300519Article in journal (Refereed)
    Abstract [en]

    Unconjugated pterins are ubiquitous molecules that participate in countless enzymatic processes and are potentially involved in the photosensitization of singlet oxygen, amino acids, and nucleotides. Following electronic excitation with UV-A light, some of these pterins degrade, producing hydrogen peroxide as the main side product. This process, which is known to take place in vivo, contributes to oxidative stress and melanocyte destruction in vitiligo. In this work, we present for the first time mechanistic insight into the formation of transient triplet species that simultaneously trigger Type I and Type II photosensitizing processes and the initiation of degradation processes. Our calculations reveal that photodegradation of 6-biopterin, which accumulates in the skin of vitiligo patients, leads to 6-formylpterin through a retro-aldol reaction, and subsequently to 6-carboxypterin through a water-mediated aldehyde oxidation. Additionally, we show that the changes in the photosensitizing potential of these systems with pH come from the modulation of their excited-state redox potentials.

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  • 8.
    Björk, Jonas
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Materials design. Linköping University, Faculty of Science & Engineering.
    Sanchez-Sanchez, Carlos
    Swiss Fed Labs Mat Sci & Technol, Switzerland; Inst Mat Sci Madrid ICMM CSIC, Spain.
    Chen, Qiang
    Max Planck Inst Polymer Res, Germany; Univ Oxford, England.
    Pignedoli, Carlo A.
    Swiss Fed Labs Mat Sci & Technol, Switzerland.
    Rosén, Johanna
    Linköping University, Department of Physics, Chemistry and Biology, Materials design. Linköping University, Faculty of Science & Engineering.
    Ruffieux, Pascal
    Swiss Fed Labs Mat Sci & Technol, Switzerland.
    Feng, Xinliang
    Tech Univ Dresden, Germany; Tech Univ Dresden, Germany.
    Narita, Akimitsu
    Max Planck Inst Polymer Res, Germany; Okinawa Inst Sci & Technol Grad Univ, Japan.
    Mullen, Klaus
    Max Planck Inst Polymer Res, Germany.
    Fasel, Roman
    Swiss Fed Labs Mat Sci & Technol, Switzerland; Univ Bern, Switzerland.
    The Role of Metal Adatoms in a Surface-Assisted Cyclodehydrogenation Reaction on a Gold Surface2022In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 61, no 49, article id e202212354Article in journal (Refereed)
    Abstract [en]

    Dehydrogenation reactions are key steps in many metal-catalyzed chemical processes and in the on-surface synthesis of atomically precise nanomaterials. The principal role of the metal substrate in these reactions is undisputed, but the role of metal adatoms remains, to a large extent, unanswered, particularly on gold substrates. Here, we discuss their importance by studying the surface-assisted cyclodehydrogenation on Au(111) as an ideal model case. We choose a polymer theoretically predicted to give one of two cyclization products depending on the presence or absence of gold adatoms. Scanning probe microscopy experiments observe only the product associated with adatoms. We challenge the prevalent understanding of surface-assisted cyclodehydrogenation, unveiling the catalytic role of adatoms and their effect on regioselectivity. The study adds new perspectives to the understanding of metal catalysis and the design of on-surface synthesis protocols for novel carbon nanomaterials.

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  • 9.
    Björk, Linnea
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry.
    Synthesis of proteophenes that can be utilized as fluorescent ligands for biological targets2019Independent thesis Advanced level (degree of Master (Two Years)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    Small fluorescent probes are important tools when studying protein aggregates involved in different neurodegenerative diseases, such as Alzheimer’s disease. Luminescent conjugated oligothiophenes have been developed and shown to be excellent ligands when studying morphology among amyloids, due to their conjugated thiophene backbone that provides them with unique photophysical properties. This kind of probes are being developed successively to enhance the specificity of their biological targets. In this project, luminescent conjugated oligothiophenes functionalized with amino acids, so called proteophenes, have been synthesized to investigate their optical properties. Since amino acids are chiral molecules, the possibility of induced chirality to the thiophene backbone was examined, as well as the proteophenes ability to work as amyloidospecific ligands for the study of protein aggregates. The synthesis of four different proteophenes are presented in this report, along with analysis results of their photophysical properties.

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  • 10.
    Björk, Linnea
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Selegård, Robert
    Linköping University, Department of Physics, Chemistry and Biology, Biophysics and bioengineering. Linköping University, Faculty of Science & Engineering.
    Bäck, Marcus
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Hammarström, Per
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Lindgren, Mikael
    Norwegian Univ Sci & Technol, Norway.
    Nilsson, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Amino-Acid Side-Chain Nanoarchitectonics for Tuning the Chiroptical Properties and Supramolecular Structure of Pentameric Oligothiophenes2024In: ChemPhotoChem, E-ISSN 2367-0932Article in journal (Refereed)
    Abstract [en]

    Oligothiophenes with specific photophysical properties and molecular organization are of great interest, since this class of materials are used in organic electronics and bioelectronics, as well as biosensing. Herein, 8 different pentameric oligothiophenes, denoted proteophenes, with different amino acid substitution patterns at distinct positions along the thiophene backbone were investigated. Spectroscopic and microscopic studies of the ligands revealed the formation of optically active self-assembled materials under acidic or basic conditions. The distinct photophysical characteristics, including induced circular dichroism, as well as the supramolecular structures of the assemblies deduced from light scattering and transmission electron microscopy, were highly influenced by the positioning of distinct amino acid moieties along the thiophene backbone. Proteophenes functionalized with only glutamate residues or these functionalities in combination with hydrophobic valine moieties formed fibrillar structures with excellent chiroptical properties under acidic conditions. In addition, the amino acid functionality at the beta-position of distinct thiophene moieties influenced the induced circular dichroism pattern observed from the proteophenes. Overall, the obtained results demonstrate how changes in the position of various amino acid functionalities, as well as the chemical nature of the amino acid side chain functionality greatly affect the optical properties as well as the architecture of the self-assembled materials. Self-assembled Proteophenes. Oligothiophenes with distinct amino acid side-chain functionalities along the conjugated backbone displayed distinct chiroptical and structural properties in acidic or alkaline solutions. The distinct photophysical characteristics, as well as the supramolecular structures of the assemblies were highly influenced by the chemical nature of the amino acid, as well as the positioning of distinct amino acid moieties along the thiophene backbone.image

  • 11.
    Bykov, Maxim
    et al.
    Howard Univ, DC 20059 USA; Carnegie Inst Sci, DC 20015 USA.
    Bykova, Elena
    Carnegie Inst Sci, DC 20015 USA.
    Ponomareva, Alena V.
    Natl Univ Sci & Technol MISIS, Russia.
    Abrikosov, Igor
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering.
    Chariton, Stella
    Univ Chicago, IL 60437 USA.
    Prakapenka, Vitali B.
    Univ Chicago, IL 60437 USA.
    Mahmood, Mohammad F.
    Howard Univ, DC 20059 USA.
    Dubrovinsky, Leonid
    Bayer Geoinst, Germany.
    Goncharov, Alexander F.
    Carnegie Inst Sci, DC 20015 USA.
    Stabilization of Polynitrogen Anions in Tantalum-Nitrogen Compounds at High Pressure2021In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 60, no 16, p. 9003-9008Article in journal (Refereed)
    Abstract [en]

    The synthesis of polynitrogen compounds is of great importance due to their potential as high-energy-density materials (HEDM), but because of the intrinsic instability of these compounds, their synthesis and stabilization is a fundamental challenge. Polymeric nitrogen units which may be stabilized in compounds with metals at high pressure are now restricted to non-branched chains with an average N-N bond order of 1.25, limiting their HEDM performances. Herein, we demonstrate the synthesis of a novel polynitrogen compound TaN5 via a direct reaction between tantalum and nitrogen in a diamond anvil cell at circa 100 GPa. TaN5 is the first example of a material containing branched all-single-bonded nitrogen chains [N-5(5-)](infinity). Apart from that we discover two novel Ta-N compounds: TaN4 with finite N-4(4-) chains and the incommensurately modulated compound TaN2-x, which is recoverable at ambient conditions.

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  • 12.
    Bykov, Maxim
    et al.
    Howard Univ, DC 20059 USA; Univ Bayreuth, Germany; Carnegie Inst Sci, DC 20015 USA.
    Chariton, Stella
    Univ Chicago, IL 60437 USA.
    Bykova, Elena
    Carnegie Inst Sci, DC 20015 USA.
    Khandarkhaeva, Saiana
    Univ Bayreuth, Germany.
    Fedotenko, Timofey
    Univ Bayreuth, Germany.
    Ponomareva, Alena V
    Natl Univ Sci and Technol MISIS, Russia.
    Tidholm, Johan
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering.
    Tasnadi, Ferenc
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering.
    Abrikosov, Igor
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering.
    Sedmak, Pavel
    European Synchrotron Radiat Facil, France.
    Prakapenka, Vitali
    Univ Chicago, IL 60437 USA.
    Hanfland, Michael
    European Synchrotron Radiat Facil, France.
    Liermann, Hanns-Peter
    DESY, Germany.
    Mahmood, Mohammad
    Howard Univ, DC 20059 USA.
    Goncharov, Alexander F.
    Carnegie Inst Sci, DC 20015 USA.
    Doubrovinckaia, Natalia
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering. Univ Bayreuth, Germany.
    Dubrovinsky, Leonid
    Univ Bayreuth, Germany.
    High-Pressure Synthesis of Metal-Inorganic Frameworks Hf4N20 center dot N-2, WN8 center dot N-2, and Os5N28 center dot 3 N-2 with Polymeric Nitrogen Linkers2020In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 59, no 26, p. 10321-10326Article in journal (Refereed)
    Abstract [en]

    Polynitrides are intrinsically thermodynamically unstable at ambient conditions and require peculiar synthetic approaches. Now, a one-step synthesis of metal-inorganic frameworks Hf4N20 center dot N2, WN 8 center dot N2, and Os5N28 center dot 3N2 via direct reactions between elements in a diamond anvil cell at pressures exceeding 100 GPa is reported. The porous frameworks (Hf4N20, WN 8, and Os5N28) are built from transition-metal atoms linked either by polymeric polydiazenediyl (polyacetylene-like) nitrogen chains or through dinitrogen units. Triply bound dinitrogen molecules occupy channels of these frameworks. Owing to conjugated polydiazenediyl chains, these compounds exhibit metallic properties. The high-pressure reaction between Hf and N2 also leads to a non-centrosymmetric polynitride Hf2N11 that features double-helix catenapoly[tetraz-1-ene-1,4-diyl] nitrogen chains [-N-N-N=N-](infinity.)

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  • 13.
    Bykov, Maxim
    et al.
    Univ Bayreuth, Germany.
    Chariton, Stella
    Univ Bayreuth, Germany.
    Fei, Hongzhan
    Univ Bayreuth, Germany.
    Fedotenko, Timofey
    Univ Bayreuth, Germany.
    Aprilis, Georgios
    Univ Bayreuth, Germany.
    Ponomareva, Alena V
    Natl Univ Sci and Technol MISIS, Russia.
    Tasnadi, Ferenc
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering.
    Abrikosov, Igor
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering.
    Merle, Benoit
    Friedrich Alexander Univ Erlangen Nurnberg FAU, Germany.
    Feldners, Patrick
    Friedrich Alexander Univ Erlangen Nurnberg FAU, Germany.
    Vogel, Sebastian
    Univ Munich LMU, Germany.
    Schnick, Wolfgang
    Univ Munich LMU, Germany.
    Prakapenka, Vitali B.
    Univ Chicago, IL 60637 USA.
    Greenberg, Eran
    Univ Chicago, IL 60637 USA.
    Hanfland, Michael
    European Synchrotron Radiat Facil, France.
    Pakhomova, Anna
    DESY, Germany.
    Liermann, Hanns-Peter
    DESY, Germany.
    Katsura, Tomoo
    Univ Bayreuth, Germany.
    Dubrovinskaia, Natalia
    Univ Bayreuth, Germany.
    Dubrovinsky, Leonid
    Univ Bayreuth, Germany.
    High-pressure synthesis of ultraincompressible hard rhenium nitride pernitride Re-2(N-2)(N)(2) stable at ambient conditions2019In: Nature Communications, E-ISSN 2041-1723, Vol. 10, article id 2994Article in journal (Refereed)
    Abstract [en]

    High-pressure synthesis in diamond anvil cells can yield unique compounds with advanced properties, but often they are either unrecoverable at ambient conditions or produced in quantity insufficient for properties characterization. Here we report the synthesis of metallic, ultraincompressible (K-0 = 428(10) GPa), and very hard (nanoindentation hardness 36.7(8) GPa) rhenium nitride pernitride Re-2(N-2)(N)(2). Unlike known transition metals pernitrides Re-2(N-2)(N)(2) contains both pernitride N-2(4-) and discrete N3- anions, which explains its exceptional properties. Re-2(N-2)(N)(2) can be obtained via a reaction between rhenium and nitrogen in a diamond anvil cell at pressures from 40 to 90 GPa and is recoverable at ambient conditions. We develop a route to scale up its synthesis through a reaction between rhenium and ammonium azide, NH4N3, in a large-volume press at 33 GPa. Although metallic bonding is typically seen incompatible with intrinsic hardness, Re-2(N-2)(N)(2) turned to be at a threshold for superhard materials.

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  • 14. Order onlineBuy this publication >>
    Bäck, Marcus
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry. Linköping University, The Institute of Technology.
    Design and Synthesis of Hepatitis C Virus NS3 Protease Inhibitors Incorporating a P2 Cyclopentane-Derived Scaffold2006Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis describes the design, synthesis and structure-activity relationships analysis of potential inhibitors targeting the hepatitis C virus (HCV) NS3 protease. Also discussed is the disease caused by HCV infection and the class of enzymes known as proteases. Furthermore are explained why such enzymes can be considered to be suitable targets for developing drugs to combat diseases in general and in particular HCV, focusing on the NS3 protease. Moreover, some strategies used to design protease inhibitors and the desired properties of potential drug candidates are briefly examined. Synthesis of linear and macrocyclic NS3 protease inhibitors comprising a designed trisubstituted cyclopentane moiety as an N-acyl-(4R)-hydroxyproline bioisostere is also addressed, and several very potent and promising compounds are evaluated.

    List of papers
    1. Potent inhibitors of the hepatitis C virus NS3 protease: use of a novel P2 cyclopentane-derived template
    Open this publication in new window or tab >>Potent inhibitors of the hepatitis C virus NS3 protease: use of a novel P2 cyclopentane-derived template
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    2006 (English)In: Bioorganic & Medicinal Chemistry, ISSN 0968-0896, E-ISSN 1464-3391, Vol. 14, no 15, p. 5136-5151Article in journal (Refereed) Published
    Abstract [en]

    The HCV NS3 protease is essential for replication of the hepatitis C virus (HCV) and therefore constitutes a promising new drug target for anti-HCV therapy. Several potent and promising HCV NS3 protease inhibitors, some of which display low nanomolar activities, were identified from a series of novel inhibitors incorporating a trisubstituted cyclopentane dicarboxylic acid moiety as a surrogate for the widely used N-acyl-(4R)-hydroxyproline in the P2 position.

    Keywords
    HCV, NS3, Protease inhibitor, Cyclopentane-derived P2 scaffold
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:liu:diva-14308 (URN)10.1016/j.bmc.2006.04.008 (DOI)
    Available from: 2007-02-21 Created: 2007-02-21 Last updated: 2017-12-13Bibliographically approved
    2. Potent Macrocyclic Inhibitors of the Hepatitis C Virus NS3 Protease. Use of Cyclopentane and Cyclopentene Derived P2-Scaffolds
    Open this publication in new window or tab >>Potent Macrocyclic Inhibitors of the Hepatitis C Virus NS3 Protease. Use of Cyclopentane and Cyclopentene Derived P2-Scaffolds
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    Manuscript (Other academic)
    Identifiers
    urn:nbn:se:liu:diva-14309 (URN)
    Available from: 2007-02-21 Created: 2007-02-21 Last updated: 2010-01-13
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  • 15.
    Bäck, Marcus
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Selegård, Robert
    Linköping University, Department of Physics, Chemistry and Biology, Biophysics and bioengineering. Linköping University, Faculty of Science & Engineering.
    Todarwal, Yogesh
    KTH Royal Inst Technol, Sweden.
    Nyström, Sofie
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Norman, Patrick
    KTH Royal Inst Technol, Sweden.
    Linares, Mathieu
    Linköping University, Department of Physics, Chemistry and Biology, Bioinformatics. Linköping University, Faculty of Science & Engineering.
    Hammarström, Per
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Lindgren, Mikael
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering. Norwegian Univ Sci & Technol, Norway.
    Nilsson, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Tyrosine Side-Chain Functionalities at Distinct Positions Determine the Chirooptical Properties and Supramolecular Structures of Pentameric Oligothiophenes2020In: ChemistryOpen, ISSN 2191-1363, Vol. 9, no 11, p. 1100-1108Article in journal (Refereed)
    Abstract [en]

    Control over the photophysical properties and molecular organization of pi-conjugated oligothiophenes is essential to their use in organic electronics. Herein we synthesized and characterized a variety of anionic pentameric oligothiophenes with different substitution patterns of L- or D-tyrosine at distinct positions along the thiophene backbone. Spectroscopic, microscopic, and theoretical studies of L- or D-tyrosine substituted pentameric oligothiophene conjugates revealed the formation of optically active pi-stacked self-assembled aggregates under acid conditions. The distinct photophysical characteristics, as well as the supramolecular structures of the assemblies, were highly influenced by the positioning of the L- or D-tyrosine moieties along the thiophene backbone. Overall, the obtained results clearly demonstrate how fundamental changes in the position of the enantiomeric side-chain functionalities greatly affect the optical properties as well as the architecture of the self-assembled supramolecular structures.

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  • 16.
    Bäcklund, Fredrik G.
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Pallbo, Jon
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Solin, Niclas
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Controlling Amyloid Fibril Formation by Partial Stirring2016In: Biopolymers, ISSN 0006-3525, E-ISSN 1097-0282, Vol. 105, no 5, p. 249-259Article in journal (Refereed)
    Abstract [en]

    Many proteins undergoes self-assembly into fibrillar structures known as amyloid fibrils. During the self-assembly process related structures, known as spherulites, can be formed. Herein we report a facile method where the balance between amyloid fibrils and spherulites can be controlled by stirring of the reaction mixture during the initial stages of the self-assembly process. Moreover, we report how this methodology can be used to prepare non-covalently functionalized amyloid fibrils. By stirring the reaction mixture continuously or for a limited time during the lag phase the fibril length, and hence the propensity to form liquid crystalline phases, can be influenced. This phenomena is utilized by preparing films consisting of aligned protein fibrils incorporating the laser dye Nile red. The resulting films display polarized Nile red fluorescence.

  • 17.
    Bäcklund, Fredrik G.
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Solin, Niclas
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Tuning the aqueous self-assembly process of insulin by a hydrophobic additive2015In: RSC ADVANCES, ISSN 2046-2069, Vol. 5, no 112, p. 92254-92262Article in journal (Refereed)
    Abstract [en]

    Biomolecular self-assembly is an efficient way of preparing soft-matter based materials. Herein we report a novel method, based on the use of insoluble additives in aqueous media, for influencing the self-assembly process. Due to their low solubility, the use of hydrophobic additives in aqueous media is problematic; however, by mixing the additive with the biomolecule in the solid state, prior to solvation, this problem can be circumvented. In the investigated self-assembly system, where bovine insulin self-assembles into spherical structures, the inclusion of the hydrophobic material α-sexithiophene (6T) results in significant changes in the self-assembly process. Under our reaction conditions, in the case of materials prepared from insulin-only the growth of spherulites typically stops at a diameter of 150μm. However, by adding 2 weight % of hydrophobic material, spherulite growth continues up to diameters in the mm-range. The spherulites incorporate 6T and are thus fluorescent. The method reported herein should be of interest to all scientists working in the field of self-assembly as the flexible materials preparation, based simply on co-grinding of commercially available materials, adds another option to influence the structure and properties of products formed by  self-assembly reactions.

  • 18.
    Bäcklund, Fredrik Gustaf
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Ajjan, Fátima Nadia
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Solin, Niclas
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Convection Induced Air-Water Interface Assembly of Amyloid FibrilsManuscript (preprint) (Other academic)
    Abstract [en]

    We report that hydrophobically modified amyloid fibrils form macroscopic films at the air-water interface. The hydrophobically modified fibrils are prepared in a two step process. First bovine insulin is ground with a hydrophobic compound. The resulting material is dissolved in acidic water and heated to induce assembly into fibrils incorporating the hydrophobic compounds. Upon dilution followed by asymmetric heating, resulting in convection flow, the fibrills form highly ordered films with thicknesses from 80 nm and up. The thickness of the film can be controlled by the fibril concentration and/or reaction time. The films contain anisotropic domains spanning several square centimeters. In addition, the films contains ordered assemblies of dyes that display emission of polarized light.

  • 19.
    Cai, Weidong
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Electronic and photonic materials. Linköping University, Faculty of Science & Engineering.
    Qin, Jiajun
    Linköping University, Department of Physics, Chemistry and Biology, Electronic and photonic materials. Linköping University, Faculty of Science & Engineering.
    Pang, Tiqiang
    Xidian Univ, Peoples R China.
    Cai, Xinyi
    Linköping University, Department of Physics, Chemistry and Biology, Electronic and photonic materials. Linköping University, Faculty of Science & Engineering.
    Jia, Renxu
    Xidian Univ, Peoples R China.
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Electronic and photonic materials. Linköping University, Faculty of Science & Engineering.
    Chirality Induced Crystal Structural Difference in Metal Halide Composites2022In: Advanced Optical Materials, ISSN 2162-7568, E-ISSN 2195-1071, Vol. 10, no 16, article id 2102140Article in journal (Refereed)
    Abstract [en]

    Incorporating chiral organic compounds into metal halide frames is a common and useful method to introduce chirality in metal halide composites. The structures of resulting racemic and chiral composites are usually considered to be nearly identical owing to similar chemical bonding. In this work, by incorporating chiral MBABr (bromide methylbenzylamine) into an inorganic frame, a significant crystallization difference between the resulting racemic and chiral metal halide composites is observed, as confirmed by both structural and spectroscopic measurements. In addition, the structural transformation in the chiral composites can also be induced by moisture, ascribed to the asymmetric hydrogen bonding in chiral materials. These results provide new insights for the future synthesis of chiral materials and open up new possibilities to advance the materials functionalities.

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  • 20.
    Cao, Guanyue
    et al.
    East China Univ Sci & Technol, Peoples R China.
    Baryshnikov, Glib
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Chen, Chen
    East China Univ Sci & Technol, Peoples R China.
    Chen, Liyuan
    East China Univ Sci & Technol, Peoples R China.
    Zhao, Tengjiao
    East China Univ Sci & Technol, Peoples R China.
    Fu, Shuyi
    East China Univ Sci & Technol, Peoples R China.
    Jiang, Zhenhui
    East China Univ Sci & Technol, Peoples R China.
    Liu, Xiujun
    East China Univ Sci & Technol, Peoples R China.
    Li, Qizhao
    East China Univ Sci & Technol, Peoples R China.
    Xie, Yongshu
    East China Univ Sci & Technol, Peoples R China.
    Li, Chengjie
    East China Univ Sci & Technol, Peoples R China.
    Porphyrindiene-Based Tandem Diels-Alder Reaction for Preparing Low-Symmetry pi-Extended Porphyrins with Push-Pull Skeletons2022In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 87, no 14, p. 9001-9010Article in journal (Refereed)
    Abstract [en]

    Tandem Diels-Alder reactions of masked porphyrindienes (i.e., sulfolenoporphyrins) with benzoquinones and stilbenes, followed by aromatization, have been developed to load porphyrin with mixed annulation units (i.e., terphenyl and naphthoquinone), furnishing the low-symmetry pi-extended porphyrins (DxAy) with push-pull skeletons. All low-symmetrical chromophores display panchromatic absorption spectra, which look like a spectral combination of symmetrical congeners (D4/A4) in a certain ratio. Among them, tD2A2 with trans-arrangement of push/pull units possesses the largest maximum centered at 766 nm with the onset around 900 nm. The fusion of the electron-deficient naphthoquinone moiety on the porphyrin core results in the approximately quantitative regulation of the E-ox1 and HOMOs (i.e., 0.10-0.13 V increase for the E-ox1 and 0.14-0.16 eV decrease for the HOMOs per naphthoquinone unit). In brief, this work provides a new way to construct low-symmetry pi-extended porphyrins with tunable properties resorting to the ratios and locations of the annulated push-pull units.

  • 21.
    Cao, Nan
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering. Tech Univ Munich, Germany.
    Yang, Biao
    Tech Univ Munich, Germany.
    Riss, Alexander
    Tech Univ Munich, Germany.
    Rosén, Johanna
    Linköping University, Department of Physics, Chemistry and Biology, Materials design. Linköping University, Faculty of Science & Engineering.
    Björk, Jonas
    Linköping University, Department of Physics, Chemistry and Biology, Materials design. Linköping University, Faculty of Science & Engineering.
    Barth, Johannes V.
    Tech Univ Munich, Germany.
    On-surface synthesis of enetriynes2023In: Nature Communications, E-ISSN 2041-1723, Vol. 14, no 1, article id 1255Article in journal (Refereed)
    Abstract [en]

    Belonging to the enyne family, enetriynes comprise a distinct electron-rich all-carbon bonding scheme. However, the lack of convenient synthesis protocols limits the associated application potential within, e.g., biochemistry and materials science. Herein we introduce a pathway for highly selective enetriyne formation via tetramerization of terminal alkynes on a Ag(100) surface. Taking advantage of a directing hydroxyl group, we steer molecular assembly and reaction processes on square lattices. Induced by O-2 exposure the terminal alkyne moieties deprotonate and organometallic bis-acetylide dimer arrays evolve. Upon subsequent thermal annealing tetrameric enetriyne-bridged compounds are generated in high yield, readily self-assembling into regular networks. We combine high-resolution scanning probe microscopy, X-ray photoelectron spectroscopy and density functional theory calculations to examine the structural features, bonding characteristics and the underlying reaction mechanism. Our study introduces an integrated strategy for the precise fabrication of functional enetriyne species, thus providing access to a distinct class of highly conjugated pi-system compounds. Enetriynes, which belong to the enyne family, are characterized by a distinct electron-rich carbon-bonding scheme. Here, the authors report the formation of enetriynes with high selectivity by tetramerization of terminal alkynes on Ag(100).

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  • 22. Order onlineBuy this publication >>
    Carlsson, Andreas
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering. Swedish National Forens Centre NFC, Linkoping, Sweden.
    Synthesis and spectroscopic characterization of emerging synthetic cannabinoids and cathinones2016Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The application of different analytical techniques is fundamental in forensic drug analysis. In the wake of the occurrence of large numbers of new psychoactive substances possessing similar chemical structures as already known ones, focus has been placed on applied criteria for their univocal identification. These criteria vary, obviously, depending on the applied technique and analytical approach. However, when two or more substances are proven to have similar analytical properties, these criteria no longer apply, which imply that complementary techniques have to be used in their differentiation.

    This work describes the synthesis of some structural analogues to synthetic cannabinoids and cathinones based on the evolving patterns in the illicit drug market. Six synthetic cannabinoids and six synthetic cathinones were synthesized, that, at the time for this study, were not as yet found in drug seizures. Further, a selection of their spectroscopic data is compared to those of already existing analogues; mainly isomers and homologues. The applied techniques were mass spectrometry (MS), Fourier transformed infrared (FTIR, gas phase) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. In total, 59 different compounds were analyzed with the  selected techniques.

    The results from comparison of spectroscopic data showed that isomeric substances may in some cases be difficult to unambiguously identify based only on their GC-MS EI spectra. On the other hand, GC-FTIR demonstrated more distinguishable spectra. The spectra for the homologous compounds showed however, that the GC-FTIR technique was less successful compared to GC-MS. Also a pronounced fragmentation pattern for some of the cathinones was found.

    In conclusion, this thesis highlights the importance of using complementary techniques for the univocal identification of synthetic cannabinoids and cathinones. By increasing the number of analogues investigated, the more may be learnt about the capabilities of different techniques for structural differentiations, and thereby providing important identification criteria leading to trustworthy forensic evidence.

    List of papers
    1. Prediction of designer drugs: synthesis and spectroscopic analysis of synthetic cannabinoid analogues of 1H-indol-3-yl(2,2,3,3-tetramethylcyclopropyl) methanone and 1H-indol-3-yl(adamantan-1-yl)methanone
    Open this publication in new window or tab >>Prediction of designer drugs: synthesis and spectroscopic analysis of synthetic cannabinoid analogues of 1H-indol-3-yl(2,2,3,3-tetramethylcyclopropyl) methanone and 1H-indol-3-yl(adamantan-1-yl)methanone
    Show others...
    2016 (English)In: Drug Testing and Analysis, ISSN 1942-7603, E-ISSN 1942-7611, Vol. 8, no 10, p. 1015-1029Article in journal (Refereed) Published
    Abstract [en]

    In this work, emergence patterns of synthetic cannabinoids were utilized in an attempt to predict those that may appear on the drug market in the future. Based on this information, two base structures of the synthetic cannabinoid analogues - (1H-indol-3-yl (2,2,3,3-tetramethylcyclopropyl) methanone and 1H-indol-3-yl(adamantan-1-yl)methanone) - together with three substituents butyl, 4-fluorobutyl and ethyl tetrahydropyran - were selected for synthesis. This resulted in a total of six synthetic cannabinoid analogues that to the authors knowledge have not yet appeared on the drug market. Spectroscopic data, including nuclearmagnetic resonance (NMR), mass spectrometry (MS), and Fourier transforminfrared (FTIR) spectroscopy (solid and gas phase), are presented for the synthesized analogues and some additional related cannabinoids. In this context, the suitability of the employed techniques for the identification of unknowns is discussed and the use of GC-FTIR as a secondary complementary technique to GC-MS is addressed. Examples of compounds that are difficult to differentiate by their mass spectra, but can be distinguished based upon their gas phase FTIR spectra are presented. Conversely, structural homologueswhere mass spectra aremore powerful than gas phase FTIR spectra for unambiguous assignments are also exemplified. This work further emphasizes that a combination of several techniques is the key to success in structural elucidations. Copyright (C) 2015 John Wiley amp; Sons, Ltd.

    Place, publisher, year, edition, pages
    WILEY-BLACKWELL, 2016
    Keywords
    drug analysis; proactive; synthetic cannabinoids; synthesis; mass spectrometry
    National Category
    Pharmaceutical Sciences
    Identifiers
    urn:nbn:se:liu:diva-132473 (URN)10.1002/dta.1904 (DOI)000384806400003 ()26526273 (PubMedID)
    Note

    Funding Agencies|Swedish Contingencies Agency (MSB)

    Available from: 2016-11-13 Created: 2016-11-12 Last updated: 2018-01-13
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  • 23.
    Cirera, B.
    et al.
    IMDEA Nanosci, Spain.
    Björk, Jonas
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering.
    Otero, R.
    IMDEA Nanosci, Spain; University of Autonoma Madrid, Spain.
    Gallego, J. M.
    CSIC, Spain.
    Miranda, R.
    IMDEA Nanosci, Spain; University of Autonoma Madrid, Spain.
    Ecija, D.
    IMDEA Nanosci, Spain.
    Efficient Lanthanide Catalyzed Debromination and Oligomeric Length-Controlled Ullmann Coupling of Aryl Halides2017In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 121, no 14, p. 8033-8041Article in journal (Refereed)
    Abstract [en]

    Lanthanide elements play a vital role in a broad range of high-tech applications, and there is an increasing interest in their catalytic activity, particularly in organo-metallics. However, their catalytic role on surfaces remains unexplored. Here, we present a scanning tunneling microscopy and density functional theory study of the debromination, contacting, and coupling of dibromine terphenyl species with Dy (f-block element) and Ag (d-block element) adatoms, respectively. We show that Dy debrominates the targeted species more efficiently than Ag adatoms at room temperature, promoting the formation of unprecedented C-Dy-C organo-metallic supramolecules versus C-Ag-C parallel chains for the Ag case. DFT calculations corroborate our results showing an almost spontaneous debromination process with Dy compared to Ag. Upon annealing, for samples containing Dy, the formation of C-Ag-C organometallic bonds and concomitant C-C coupling is inhibited, giving rise to a self-assembly of debrominated monomers, showing only a minority number of covalent dimes species. For samples without Dy covalent chains of irregular length are promoted. Our studies open new avenues for using lanthanide elements as efficient dehalogenation catalysts. Furthermore, we illustrate their potential as inhibitors of uncontrolled C-C coupling reactions, of great relevance for fine-tuning the length of polymeric compounds.

  • 24.
    Corpas, Javier
    et al.
    Univ Autonoma Madrid UAM, Spain.
    Arpa González, Enrique Manuel
    Linköping University, Department of Physics, Chemistry and Biology, Bioinformatics. Linköping University, Faculty of Science & Engineering.
    Lapierre, Romain
    Univ Autonoma Madrid UAM, Spain.
    Corral, Ines
    UAM, Spain; UAM, Spain.
    Mauleon, Pablo
    Univ Autonoma Madrid UAM, Spain; UAM, Spain.
    Arrayas, Ramon Gomez
    Univ Autonoma Madrid UAM, Spain; UAM, Spain.
    Carretero, Juan C.
    UAM, Spain; UAM, Spain.
    Interplay between the Directing Group and Multifunctional Acetate Ligand in Pd-Catalyzed anti-Acetoxylation of Unsymmetrical Dialkyl-Substituted Alkynes2022In: ACS Catalysis, ISSN 2155-5435, E-ISSN 2155-5435, Vol. 12, no 11, p. 6596-6605Article in journal (Refereed)
    Abstract [en]

    The cooperative action of the acetate ligand, the 2-pyridyl sulfonyl (SO2Py) directing group on the alkyne substrate,and the palladium catalyst has been shown to be crucial forcontrolling reactivity, regioselectivity, and stereoselectivity in theacetoxylation of unsymmetrical internal alkynes under mildreaction conditions. The corresponding alkenyl acetates wereobtained in good yields with complete levels of beta-regioselectivityandanti-acetoxypalladation stereocontrol. Experimental andcomputational analyses provide insight into the reasons behindthis delicate interplay between the ligand, directing group, and themetal in the reaction mechanism. In fact, these studies unveil themultiple important roles of the acetate ligand in the coordinationsphere at the Pd center: (i) it brings the acetic acid reagent into close proximity to the metal to allow the simultaneous activation ofthe alkyne and the acetic acid, (ii) it serves as an inner-sphere base while enhancing the nucleophilicity of the acid, and (iii) it acts asan intramolecular acid to facilitate protodemetalation and regeneration of the catalyst. Further insight into the origin of the observedregiocontrol is provided by the mapping of potential energy profiles and distortion-interaction analysis

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  • 25.
    Corpas, Javier
    et al.
    Univ Autonoma Madrid UAM, Spain.
    Gomez-Mendoza, Miguel
    IMDEA Energy Inst, Spain.
    Arpa Gonzalez, Enrique Manuel
    Linköping University, Department of Physics, Chemistry and Biology, Bioinformatics. Linköping University, Faculty of Science & Engineering.
    de la Pena OShea, Victor A.
    IMDEA Energy Inst, Spain.
    Durbeej, Bo
    Linköping University, Department of Physics, Chemistry and Biology, Bioinformatics. Linköping University, Faculty of Science & Engineering.
    Carretero, Juan C.
    Univ Autonoma Madrid UAM, Spain.
    Mauleon, Pablo
    Univ Autonoma Madrid UAM, Spain.
    Arrayas, Ramon Gomez
    Univ Autonoma Madrid UAM, Spain.
    Iterative Dual-Metal and Energy Transfer Catalysis Enables Stereodivergence in Alkyne Difunctionalization: Carboboration as Case Study2023In: ACS Catalysis, ISSN 2155-5435, E-ISSN 2155-5435, Vol. 13, no 22, p. 14914-14927Article in journal (Refereed)
    Abstract [en]

    Stereochemically defined tetrasubstituted olefins are widespread structural elements of organic molecules and key intermediates in organic synthesis. However, flexible methods enabling stereodivergent access to E and Z isomers of fully substituted alkenes from a common precursor represent a significant challenge and are actively sought after in catalysis, especially those amenable to complex multifunctional molecules. Herein, we demonstrate that iterative dual-metal and energy transfer catalysis constitutes a unique platform for achieving stereodivergence in the difunctionalization of internal alkynes. The utility of this approach is showcased by the stereodivergent synthesis of both stereoisomers of tetrasubstituted beta-boryl acrylates from internal alkynoates with excellent stereocontrol via sequential carboboration and photoisomerization. The reluctance of electron-deficient internal alkynes to undergo catalytic carboboration has been overcome through cooperative Cu/Pd-catalysis, whereas an Ir complex was identified as a versatile sensitizer that is able to photoisomerize the resulting sterically crowded alkenes. Mechanistic studies by means of quantum-chemical calculations, quenching experiments, and transient absorption spectroscopy have been applied to unveil the mechanism of both steps.

  • 26.
    Damas, Giane Benvinda
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering. Uppsala Univ, Sweden.
    Ivashchenko, Dmytro A.
    Univ Lyon 1, France.
    Rivalta, Ivan
    Univ Lyon 1, France; Univ Bologna, Italy.
    Araujo, C. Moyses
    Uppsala Univ, Sweden; Karlstad Univ, Sweden.
    Carbon dioxide reduction mechanism on Ru-based electrocatalysts [Ru(bpy)(2)(CO)(2)](2+): insights from first-principles theory2021In: Sustainable Energy & Fuels, E-ISSN 2398-4902, Vol. 5, no 23, p. 6066-6076Article in journal (Refereed)
    Abstract [en]

    Solar fuel production through the so-called artificial photosynthesis has attracted a great deal of attention to the development of a new world energy matrix that is renewable and environmentally friendly. This process is characterized by light absorption with enough photon energy to generate conduction electrons, which drive the carbon dioxide reduction to produce organic fuels. It is also common to couple Ru-complex electrocatalysts to form a more efficient and selective hybrid system for this application. In this work, we have undertaken a thorough investigation of the redox reaction mechanism of Ru-based electrocatalysts by means of density functional theory (DFT) methods under the experimental conditions that have been previously reported. More specifically, we have studied the electrochemistry and catalytic activity of the [Ru(bpy)(2)(CO)(2)](2+) coordination complex. Our theoretical assessment supports the following catalytic cycle: (i) [Ru(bpy)(2)(CO)(2)](2+) is transformed into [Ru(bpy)(2)(CO)](0) upon two-electron reduction and CO release; (ii) [Ru(bpy)(2)(CO)](0) is protonated to form the [Ru(bpy)(2)(CO)H](+) hydride complex; (iii) CO2 is activated by the hydride complex through an electrophilic addition to form the [Ru(bpy)(2)(CO)(OCHO)](+) intermediate; (iv) the resulting formic acid ligand is released in solution; and, finally, (v) the CO ligand is reattached to the complex to recover the initial [Ru(bpy)(2)(CO)(2)](2+) catalyst.

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  • 27.
    Danielsen, Edevardt Johan
    et al.
    Linköping University, Department of Thematic Studies, Tema Environmental Change.
    Jonsson Valderrama, Alexandra
    Linköping University, Department of Thematic Studies, Tema Environmental Change.
    Methane and Carbon Dioxide Emissions From Three Smallscale Hydropower Stations in South of Sweden2022Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
    Abstract [en]

    Over the past decades, evidence show that the anthropogenetic greenhouse gases (GHG) emissions of carbon dioxide (CO₂) and methane (CH₄) are the main drivers behind global warming and are becoming stronger. Globally, hydropower is among the main sources of renewable energy and the popular notion that hydropower electricity is carbon neutral has been under debate as evidence from measurements in different regions of the globe show significant and highly variable carbon emissions from hydropower reservoirs. But these global estimates are still highly uncertain since they are restricted to a few locations in the south of Europe, North America, and South America, and lack both the temporal and spatial variability in addition to some of the flux pathways (often downstream emission and degassing). This study assesses the CH4 and CO₂ emissions from reservoirs associated to three small hydropower stations in the south of Sweden and aims to understand potential spatial and temporal variability in the temperate region. The study performed flux measurements of CH4 and CO₂, an analysis of CH4 and DIC concentration in the water, and a depth profile of temperature, DO, CH4 and DIC at the hydropower station’s reservoirs. In summation this study finds significant CH4 and DIC concentrations, as well as CH4 and CO₂emissions from the studied reservoirs. The findings of this study underline the notion that hydropower might be a `blind spot` in the Swedish GHG budget report, and if so, the carbon emissions from hydropower electricity need to be re-evaluated.

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  • 28.
    Das, Biswanath
    et al.
    Lund University, Sweden.
    Lee, Bao-Lin
    Stockholm University, Sweden.
    Karlsson, Erik A.
    Stockholm University, Sweden.
    Akermark, Torbjorn
    Stockholm University, Sweden.
    Shatskiy, Andrey
    Stockholm University, Sweden.
    Demeshko, Serhiy
    University of Gottingen, Germany.
    Liao, Rong-Zhen
    Huazhong University of Science and Technology, Peoples R China.
    Laine, Tanja M.
    Stockholm University, Sweden.
    Haukka, Matti
    University of Jyvaskyla, Finland.
    Zeglio, Erica
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Abdel-Magied, Ahmed F.
    Stockholm University, Sweden.
    Siegbahn, Per E. M.
    Stockholm University, Sweden.
    Meyer, Franc
    University of Gottingen, Germany.
    Karkas, Markus D.
    Stockholm University, Sweden.
    Johnston, Eric V.
    Stockholm University, Sweden.
    Nordlander, Ebbe
    Lund University, Sweden.
    Åkermark, Bjorn
    Stockholm University, Sweden.
    Water oxidation catalyzed by molecular di- and nonanuclear Fe complexes: importance of a proper ligand framework2016In: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, Vol. 45, no 34, p. 13289-13293Article in journal (Refereed)
    Abstract [en]

    The synthesis of two molecular iron complexes, a dinuclear iron(III,III) complex and a nonanuclear iron complex, based on the di-nucleating ligand 2,2-(2-hydroxy-5-methyl-1,3-phenylene)bis(1H-benzo[d]imidazole-4-carboxylic acid) is described. The two iron complexes were found to drive the oxidation of water by the one-electron oxidant [Ru(bpy)(3)](3+).

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  • 29.
    Derelöv, Sara
    Linköping University, Department of Physics, Chemistry and Biology.
    Investigation of the effect of waterwork sludge on the pre-precipitation at the wastewater treatment plant in Norrköping2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
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    Investigation of the effect of waterwork sludge on the pre-precipitation at the wastewater treatment plant in Norrköping
  • 30. Order onlineBuy this publication >>
    Elgland, Mathias
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Synthesis and application of β-configured [18/19F]FDGs: Novel prosthetic CuAAC click chemistry fluoroglycosylation tools for amyloid PET imaging and cancer theranostics2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Positron emission tomography (PET) is a non-invasive imaging method that renders three-dimensional images of tissue that selectively has taken up a radiolabelled organic compound, referred to as a radiotracer. This excellent technique provides clinicians with a tool to monitor disease progression and to evaluate how the patient respond to treatment. The by far most widely employed radiotracer in PET is called 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG), which is often referred to as the golden standard in PET. From a molecular perspective, [18F]FDG is an analogue of glucose where a hydroxyl group has been replaced with a radioactive fluorine atom (18F). It is well known that covalent attachment of carbohydrates (i.e., glycosylation) to biomolecules tend to improve their properties in the body, in terms of; improved pharmacokinetics, increased metabolic stability and faster clearance from blood and other non-specific tissue. It is therefore natural to pursuit the development of a [18F]fluoroglycosylation method where [18F]FDG is chemically conjugated to a ligand with high affinity for a given biological target (e.g., tumors or disease-associated protein aggregates).

    This thesis describes a novel [18F]fluoroglycosylation method that in a simple and general manner facilitate the conjugation of [18F]FDG to biological ligands using click chemistry. The utility of the developed [18F]fluoroglycosylation method is demonstrated by radiolabelling of curcumin, thus forming a tracer that may be employed for diagnosis of Alzheimer’s disease. Moreover, a set of oligothiophenes were fluoroglycosylated for potential diagnosis of Alzheimer’s disease but also for other much rarer protein misfolding diseases (e.g., Creutzfeldt-Jakob disease and systemic amyloidosis). In addition, the synthesis of a series of 19F-fluoroglycosylated porphyrins is described which exhibited promising properties not only to detect but also to treat melanoma cancer. Lastly, the synthesis of a set of 19F-fluorinated E-stilbenes, structurally based on the antioxidant resveratrol is presented. The E-stilbenes were evaluated for their capacity to spectrally distinguish between native and protofibrillar transthyretin in the pursuit of finding diagnostic markers for the rare but severe disease, transthyretin amyloidosis.

    List of papers
    1. beta-Configured clickable [F-18] FDGs as novel F-18-fluoroglycosylation tools for PET
    Open this publication in new window or tab >>beta-Configured clickable [F-18] FDGs as novel F-18-fluoroglycosylation tools for PET
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    2017 (English)In: New Journal of Chemistry, ISSN 1144-0546, E-ISSN 1369-9261, Vol. 41, no 18, p. 10231-10236Article in journal (Refereed) Published
    Abstract [en]

    In oncology and neurology the F-18-radiolabeled glucose analogue 2-deoxy-2-[F-18]fluoro-D-glucose ([F-18]FDG) is by far the most commonly employed metabolic imaging agent for positron emission tomography (PET). Herein, we report a novel synthetic route to beta-configured mannopyranoside precursors and a chemoselective F-18-fluoroglycosylation method that employ two b-configured [F-18]FDG derivatives equipped with either a terminal azide or alkyne aglycon respectively, for use as a CuAAC clickable tool set for PET. The b-configured precursors provided the corresponding [F-18]FDGs in a radiochemical yield of 77-88%. Further, the clickability of these [F-18]FDGs was investigated by click coupling to the suitably functionalized Fmoc-protected amino acids, Fmoc-N-(propargyl)-glycine and Fmoc-3-azido-L-alanine, which provided the F-18-fluoroglycosylated amino acid conjugates in radiochemical yields of 75-83%. The F-18-fluoroglycosylated amino acids presented herein constitute a new and interesting class of metabolic PET radiotracers.

    Place, publisher, year, edition, pages
    ROYAL SOC CHEMISTRY, 2017
    National Category
    Organic Chemistry
    Identifiers
    urn:nbn:se:liu:diva-141934 (URN)10.1039/c7nj00716g (DOI)000411767400073 ()
    Note

    Funding Agencies|Swedish Foundation for Strategic Research; Swedish Research Council

    Available from: 2017-10-13 Created: 2017-10-13 Last updated: 2018-02-21
    2. Novel Trans-Stilbene-based Fluorophores as Probes for Spectral Discrimination of Native and Protofibrillar Transthyretin
    Open this publication in new window or tab >>Novel Trans-Stilbene-based Fluorophores as Probes for Spectral Discrimination of Native and Protofibrillar Transthyretin
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    2016 (English)In: ACS Chemical Neuroscience, E-ISSN 1948-7193, Vol. 7, no 7, p. 924-940Article in journal (Refereed) Published
    Abstract [en]

    Accumulation of misfolded transthyretin (TTR) as amyloid fibrils causes various human disorders. Native transthyretin is a neurotrophic protein and is a putative extracellular molecular chaperone. Several fluorophores have been shown in vitro to bind selectively to native TTR. Other compounds, such as thioflavin T, bind TTR amyloid fibrils. The probe 1-anilinonaphthalene-8-sulfonate (ANS) binds to both native and fibrillar TTR, becoming highly fluorescent, but with indistinguishable emission spectra for native and fibrillar TTR. Herein we report our efforts to develop a fluorescent small molecule capable of binding both native and misfolded protofibrillar TTR, providing distinguishable emission spectra. We used microwave synthesis for efficient production of a small library of trans-stilbenes and fluorescence spectral screening of their binding properties. We synthesized and tested 22 trans-stilbenes displaying a variety of functional groups. We successfully developed two naphthyl-based trans-stilbenes probes that detect both TTR states at physiological concentrations. The compounds bound with nanomolar to micromolar affinities and displayed distinct emission maxima upon binding native or misfolded protofibrillar TTR (>100 nm difference). The probes were mainly responsive to environment polarity providing evidence for the divergent hydrophobic structure of the binding sites of these protein conformational states. Furthermore, we were able to successfully use one of these probes to quantify the relative amounts of native and protofibrillar TTR in a dynamic equilibrium. In conclusion, we identified two trans-stilbene-based fluorescent probes, (E)-4-(2-(naphthalen-1-yl)vinyl)benzene-1,2-diol (11) and (E)-4-(2-(naphthalen-2-yl)vinyl)benzene-1,2-diol (14), that bind native and protofibrillar TTR, providing a wide difference in emission maxima allowing conformational discrimination by fluorescence spectroscopy. We expect these novel molecules to serve as important chemical biology research tools in studies of TTR folding and misfolding.

    Place, publisher, year, edition, pages
    American Chemical Society (ACS), 2016
    Keywords
    transthyretin, amyloid, stilbene, fluorescence, probe, spectrum
    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:liu:diva-122842 (URN)10.1021/acschemneuro.6b00062 (DOI)000380297500009 ()27144293 (PubMedID)
    Note

    At the time for thesis presentation publication was in status: Manuscript

    Funding agencies:The work was supported by Goran Gustafsson's Foundation (PH), The Swedish Research Council (PH), The Linkoping center for systemic neuroscience, LiU-Neuro, (XW), and Sven and Lilly Lawski's foundation (ME).

    Available from: 2015-11-26 Created: 2015-11-26 Last updated: 2023-08-28Bibliographically approved
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    Synthesis and application of β-configured [18/19F]FDGs: Novel prosthetic CuAAC click chemistry fluoroglycosylation tools for amyloid PET imaging and cancer theranostics
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  • 31.
    Elgland, Mathias
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Nordeman, P.
    Uppsala University, Sweden.
    Fyrner, Timmy
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Antoni, G.
    Uppsala University, Sweden.
    Nilsson, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Konradsson, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    beta-Configured clickable [F-18] FDGs as novel F-18-fluoroglycosylation tools for PET2017In: New Journal of Chemistry, ISSN 1144-0546, E-ISSN 1369-9261, Vol. 41, no 18, p. 10231-10236Article in journal (Refereed)
    Abstract [en]

    In oncology and neurology the F-18-radiolabeled glucose analogue 2-deoxy-2-[F-18]fluoro-D-glucose ([F-18]FDG) is by far the most commonly employed metabolic imaging agent for positron emission tomography (PET). Herein, we report a novel synthetic route to beta-configured mannopyranoside precursors and a chemoselective F-18-fluoroglycosylation method that employ two b-configured [F-18]FDG derivatives equipped with either a terminal azide or alkyne aglycon respectively, for use as a CuAAC clickable tool set for PET. The b-configured precursors provided the corresponding [F-18]FDGs in a radiochemical yield of 77-88%. Further, the clickability of these [F-18]FDGs was investigated by click coupling to the suitably functionalized Fmoc-protected amino acids, Fmoc-N-(propargyl)-glycine and Fmoc-3-azido-L-alanine, which provided the F-18-fluoroglycosylated amino acid conjugates in radiochemical yields of 75-83%. The F-18-fluoroglycosylated amino acids presented herein constitute a new and interesting class of metabolic PET radiotracers.

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  • 32.
    Fors, Jonathan
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Modeling and OpenFOAM simulation of streamers in transformer oil2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Electric breakdown in power transformers is preceded by pre-breakdown events such as streamers. The understanding of these phenomena is important in order to optimize liquid insulation systems. Earlier works have derived a model that describes streamers in transformer oil and utilized a finite element method to produce numerical solutions. This research investigates the consequences of changing the numerical method to a finite volume-based solver implemented in OpenFOAM. Using a standardized needle-sphere geometry, a number of oil and voltage combinations were simulated, and the results are for the most part similar to those produced by the previous method. In cases with differing results the change is attributed to the more stable numerical performance of the OpenFOAM solver. A proof of concept for the extension of the simulation from a two-dimensional axial symmetry to three dimensions is also presented.

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  • 33.
    Fyrner, Timmy
    Linköping University, The Department of Physics, Chemistry and Biology.
    Synthesis of Structures Related to Antifreeze Glycoproteins2005Independent thesis Advanced level (degree of Magister), 20 points / 30 hpStudent thesis
    Abstract [en]

    In this thesis, synthesis of structures related to antifreeze glycoproteins (AFGPs) are presented. Synthetic routes to a protected carbohydrate derivative, 2,3,4,6-tetra-O-benzyl-β-galactopyranosyl-(1→3)-2-deoxy-2-azido-4,6-di-O-benzyl-β-D-thio-1-galactopyranoside, and a tBu-Ala-Thr-Ala-Fmoc tripeptide, are described. These compounds are meant to be used in the assembly of AFGPs and analogues thereof. A Gal-GlcN disaccharide was synthesized via glycosylation between the donor, bromo-2-O-benzoyl-3,4,6-tri-O-benzyl-α-Dgalactopyranoside, and acceptor, ethyl 4,6-O-benzylidene-2-deoxy-2-N-phthalimido-β-D-1-thio-glucopyranoside, using silver triflate activation. Subsequent epimerization to a Gal-GalN disaccharide was achieved using Moffatt oxidation followed by L-selectride® reduction. The tripeptide was synthesized in a short and convenient manner using solid phase peptide synthesis with immobilized Fmoc-Ala on Wang® resins as starting point.

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  • 34.
    Gao, Shimin
    et al.
    East China Univ Sci & Technol, Peoples R China.
    Li, Chengjie
    East China Univ Sci & Technol, Peoples R China.
    Baryshnikov, Glib
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering. Bohdan Khmelnytsky Natl Univ, Ukraine.
    Agren, Hans
    Uppsala Univ, Sweden.
    Li, Qizhao
    East China Univ Sci & Technol, Peoples R China.
    Xie, Yongshu
    East China Univ Sci & Technol, Peoples R China.
    Stable thiophene-embedded N-confused homoporphyrins: Partial conjugation, fusion and fluoride binding2021In: Dyes and pigments, ISSN 0143-7208, E-ISSN 1873-3743, Vol. 194, article id 109612Article in journal (Refereed)
    Abstract [en]

    In the past decades, porphyrin analogues have attracted increasing attention in light of their unique properties and potential applications in various areas. In this work, novel nonconjugated thiophene-embedded N-confused homoporphyrins 1 and 2 as well as a fully-conjugated N-fused homoporphyrin 3 have been prepared through acid-catalyzed condensation reactions followed by oxidation. Both 1 and 2 comprise two meso-sp3-carbon atoms. However, they are insensitive to the air or common oxidants. Single crystal X-ray diffraction analysis reveals that 2 adopts a highly distorted boat-like conformation, with the NH moieties of two pyrrolic units pointing outwards and an O atom attached to the alpha position of the N-confused pyrrole unit. As a result, hydrogen-bonded dimers are formed through the intermolecular hydrogen bonds between the lactam-like moieties. In contrast to the highly distorted structure of 2, N-fused homoporphyrin 3 contains a unique 5,5,5-tricyclic fused ring, and thus demonstrates a relatively coplanar conformation except one inverted pyrrole unit. Because of the different structural characters, 3 exhibits F- binding behavior distinct from that of 1 and 2.

  • 35.
    Garcia-Iglesias, Miguel
    et al.
    Eindhoven University of Technology, Netherlands.
    de Waal, Bas F. M.
    Eindhoven University of Technology, Netherlands.
    Gorbunov, Andrey V.
    Eindhoven University of Technology, Netherlands.
    Palmans, Anja R. A.
    Eindhoven University of Technology, Netherlands.
    Kemerink, Martijn
    Linköping University, Department of Physics, Chemistry and Biology, Complex Materials and Devices. Linköping University, Faculty of Science & Engineering. Eindhoven University of Technology, Netherlands.
    Meijer, E. W.
    Eindhoven University of Technology, Netherlands.
    A Versatile Method for the Preparation of Ferroelectric Supramolecular Materials via Radical End-Functionalization of Vinylidene Fluoride Oligomers2016In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 138, no 19, p. 6217-6223Article in journal (Refereed)
    Abstract [en]

    A synthetic method for the end-functionalization of vinylidene fluoride oligomers (OVDF) via a radical reaction between terminal olefins and I-OVDF is described. The method shows a wide substrate scope and excellent conversions, and permits the preparation of different disc-shaped cores such as benzene-1,3,5-tricarboxamides (BTAs), perylenes bisimide and phthalocyanines (Pc) bearing three to eight ferroelectric oligomers at their periphery. The formation, purity, OVDF conformation, and morphology of the final adducts has been assessed by a combination of techniques, such as NMR, size exclusion chromatography, differential scanning calorimetry, polarized optical microscopy, and atomic force microscopy. Finally, PBI-OVDF and Pc-OVDF materials show ferroelectric hysteresis behavior together with high remnant polarizations, with values as high as P-r approximate to 37 mC/m(2) for Pc-OVDF. This work demonstrates the potential of preparing a new set of ferroelectric materials simply by attaching OVDF oligomers to different small molecules. The use of carefully chosen small molecules paves the way to new functional materials in which ferroelectricity and electrical conductivity or light-harvesting properties coexist in a single compound.

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  • 36. Order onlineBuy this publication >>
    Ghorbani Shiraz, Hamid
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Electrochemical reduction of protons and organic molecules in hydrogen technologies: Liquid Organic Hydrogen carrier and Hydrogen Evolution2022Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In accordance with preventable actions to mitigate the effect of climate change in the modern societal applications, renewable energy is an unavoidable and decisive factor in the energy industry. The energy sources that offer non-depleted and environment-friendly pathways for the energy sector are in focus. Amongst, hydrogen has been defined as one of the best candidates to meet the criteria such as high energy-content and zero-emission of CO2, and of course, renewability. In this work, we focused on the areas of hydrogen generation and hydrogen storage.

    In the first part, we employed an inorganic electrocatalyst (nanosheets) to drive the hydrogen evolution reaction (HER), where we proved that the overpotential of few millivolts (0.016 V) is enough to run the HER reaction. We studied the effect of interlayer gap (for the nanosheets) on the catalytic performance. The chemical intercalation showed a huge effect for the suppression of the HER, which could be applicable for the devices like batteries the formation of any gaseous species has detrimental effect on the performance. It should not be left unmentioned that the measurements were carried out in a platinum group metal free (PGM-free) system, where graphite felt were used as a counter electrode, to avoid any platinum contamination. Next, we investigated the effect of oxygen poisoning on both pristine electrocatalyst and intercalated one. The XPS and UPS measurements confirmed the formation of oxygen-containing groups on the electrocatalysts. Electrochemical measurements showed the increase of the overpotential toward HER as the electrocatalysts are exposed to air for longer time. However, study of the hydrogen oxidation reaction (HOR) showed that there is an optimum concentration of oxygenic functional groups that can lead to a high current density of HOR process. The study of exchange current density showed that, after 10 days of exposure of electrocatalyst to atmospheric air, pristine sample possesses the best performance toward HER and intercalated one shows the highest performance for the HOR.  

    In the other section, hydrogen storage for the organic redox-active molecule (dissolved in organic solvent) was studied. One of the main problems in hydrogen economy concept, is the storage of the hydrogen for transportation. The new concept of Liquid Organic Hydrogen Carrier (LOHC) offers a low-cost and safe approach to this challenge. Herein, we demonstrated an electrochemical pathway to hydrogenate the organic system via conversion of proton of a proton donor into a covalent-bonded hydrogen, through a proton coupled electron transfer (PCET) reaction of 2nH+ + 2ne¯ + Rox nH2Rred. Here, we studied the 9-fluorenone/fluorenol (Fnone/Fnol) as a model PCET reaction. The electrochemical activation of starting component of (Fnone), through two successive electron transfers was investigated with in-situ and operando spectroscopies purely, and in presence of different proton donors of different reactivity. We succeed to both quantify and qualify the investigated the reaction. The hydrogen release step was demonstrated chemically with the aid of catalyst.  

    To conclude, we employed a PGM-free system to demonstrate and characterize a high performing electrocatalyst for hydrogen evolution. Surprisingly, HOR was revealed to perform well using the oxygen poisoned electrocatalyst for HER. In the other section of this work, an electrochemical assisted synthesis of LOHC, in the lab-scale, was proved. A PCET pathway was conceptualized with mechanistic insight. Our work opens new avenue for the technology of hydrogenation of LOHC as we showed for the first time that this could be realized by electrochemistry without the need of hydrogen gas as a prerequisite. We believe that in the future both works could contribute slightly to the concept of the hydrogen economy.   

    List of papers
    1. Towards electrochemical hydrogen storage in liquid organic hydrogen carriers via proton-coupled electron transfers
    Open this publication in new window or tab >>Towards electrochemical hydrogen storage in liquid organic hydrogen carriers via proton-coupled electron transfers
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    2022 (English)In: Journal of Energy Challenges and Mechanics, E-ISSN 2056-9386, Vol. 73, p. 292-300Article in journal (Refereed) Published
    Abstract [en]

    Green hydrogen is identified as one of the prime clean energy carriers due to its high energy density and a zero emission of CO2. A possible solution for the transport of H2 in a safe and low-cost way is in the form of liquid organic hydrogen carriers (LOHCs). As an alternative to loading LOHC with H2 via a two-step procedure involving preliminary electrolytic production of H2 and subsequent chemical hydrogenation of the LOHC, we explore here the possibility of electrochemical hydrogen storage (EHS) via conversion of proton of a proton donor into a hydrogen atom involved in covalent bonds with the LOHC (R) via a protoncoupled electron transfer (PCET) reaction: . We chose 9-fluorenone/ fluorenol (Fnone/Fnol) conversion as such a model PCET reaction. The electrochemical activation of Fnone via two sequential electron transfers was monitored with in-situ and operando spectroscopies in absence and in presence of different alcohols as proton donors of different reactivity, which enabled us to both quantify and get the mechanistic insight on PCET. The possibility of hydrogen extraction from the loaded carrier molecule was illustrated by chemical activation.

    Place, publisher, year, edition, pages
    Elsevier, 2022
    Keywords
    Proton -coupled electron transfer; Electrochemical hydrogen storage; Hydrogen bonding agent; Anion-radical; Comproportionation
    National Category
    Organic Chemistry
    Identifiers
    urn:nbn:se:liu:diva-187281 (URN)10.1016/j.jechem.2022.06.015 (DOI)000829348500004 ()
    Note

    Funding Agencies|Swedish Research Council [2016-05990]; Knut and Alice Wallenberg Foun-dation [H2O2]; Swedish Government Strategic Research Area in Materials Science on Advanced Functional Mate-rials at Link?ping University [2009-00971]

    Available from: 2022-08-17 Created: 2022-08-17 Last updated: 2023-05-25
    2. 3R-TaS2 as an Intercalation-Dependent Electrified Interface for Hydrogen Reduction and Oxidation Reactions
    Open this publication in new window or tab >>3R-TaS2 as an Intercalation-Dependent Electrified Interface for Hydrogen Reduction and Oxidation Reactions
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    2022 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 126, no 40, p. 17056-17065Article in journal (Refereed) Published
    Abstract [en]

    Hydrogen technology, as a future breakthrough for the energy industry, has been defined as an environmentally friendly, renewable, and high-power energy carrier. The green production of hydrogen, which mainly relies on electrocatalysts, is limited by the high cost and/ or the performance of the catalytic system. Recently, studies have been conducted in search of bifunctional electrocatalysts accelerating both the hydrogen evolution reaction (HER) and the hydrogen oxidation reaction (HOR). Herein, we report the investigation of the high efficiency bifunctional electrocatalyst TaS2 for both the HER and the HOR along with the asymmetric effect of inhibition by organic intercalation. The linear organic agent, to boost the electron donor property and to ease the process of intercalation, provides a higher interlayer gap in the tandem structure of utilized nanosheets. XRD and XPS data reveal an increase in the interlayer distance of 22%. The HER and the HOR were characterized in a Pt group metal-free electrochemical system. The pristine sample shows a low overpotential of -0.016 Vat the onset. The intercalated sample demonstrates a large shift in its performance for the HER. It is revealed that the intercalation is a potential key strategy for tuning the performance of this family of catalysts. The inhibition of the HER by intercalation is considered as the increase in the operational window of a water-based electrolyte on a negative electrode, which is relevant to technologies of electrochemical energy storage.

    Place, publisher, year, edition, pages
    American Chemical Society (ACS), 2022
    National Category
    Other Chemical Engineering
    Identifiers
    urn:nbn:se:liu:diva-189795 (URN)10.1021/acs.jpcc.2c04290 (DOI)000869704900001 ()
    Note

    Funding Agencies|Swedish Research Council [VR 2016-05990]; Knut and Alice Wallenberg Foundation [KAW 2019.0604, 2021.0195]; Karl Erik Onnesjos Foundation; Swedish Government Strategic Research Area in Materials Science on Advanced Functional Materials at Linkoping University (Faculty Grant SFO-MatLiU) [2009-00971]

    Available from: 2022-11-08 Created: 2022-11-08 Last updated: 2023-12-06Bibliographically approved
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  • 37.
    Ghorbani Shiraz, Hamid
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Vagin, Mikhail
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Ruoko, Tero-Petri
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering. Tampere Univ, Finland.
    Gueskine, Viktor
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Karon, Krzysztof
    Silesian Tech Univ, Poland.
    Lapkowski, Mieczyslaw
    Silesian Tech Univ, Poland.
    Abrahamsson, Tobias
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Ederth, Thomas
    Linköping University, Department of Physics, Chemistry and Biology, Biophysics and bioengineering. Linköping University, Faculty of Science & Engineering.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Crispin, Xavier
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Towards electrochemical hydrogen storage in liquid organic hydrogen carriers via proton-coupled electron transfers2022In: Journal of Energy Challenges and Mechanics, E-ISSN 2056-9386, Vol. 73, p. 292-300Article in journal (Refereed)
    Abstract [en]

    Green hydrogen is identified as one of the prime clean energy carriers due to its high energy density and a zero emission of CO2. A possible solution for the transport of H2 in a safe and low-cost way is in the form of liquid organic hydrogen carriers (LOHCs). As an alternative to loading LOHC with H2 via a two-step procedure involving preliminary electrolytic production of H2 and subsequent chemical hydrogenation of the LOHC, we explore here the possibility of electrochemical hydrogen storage (EHS) via conversion of proton of a proton donor into a hydrogen atom involved in covalent bonds with the LOHC (R) via a protoncoupled electron transfer (PCET) reaction: . We chose 9-fluorenone/ fluorenol (Fnone/Fnol) conversion as such a model PCET reaction. The electrochemical activation of Fnone via two sequential electron transfers was monitored with in-situ and operando spectroscopies in absence and in presence of different alcohols as proton donors of different reactivity, which enabled us to both quantify and get the mechanistic insight on PCET. The possibility of hydrogen extraction from the loaded carrier molecule was illustrated by chemical activation.

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    fulltext
  • 38.
    Goossens, Nick
    et al.
    Katholieke Univ Leuven, Belgium.
    Lambrinou, Konstantina
    Univ Huddersfield, England.
    Tunca, Bensu
    Katholieke Univ Leuven, Belgium.
    Kotasthane, Vrushali
    Texas A&M Univ, TX 77843 USA.
    Gonzalez, Miriam C. Rodriguez
    Katholieke Univ Leuven, Belgium.
    Basylevska, Anastasiia
    Katholieke Univ Leuven, Belgium.
    Persson, Per O A
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    De Feyter, Steven
    Katholieke Univ Leuven, Belgium.
    Radovic, Miladin
    Texas A&M Univ, TX 77843 USA.
    Molina-Lopez, Francisco
    Katholieke Univ Leuven, Belgium.
    Vleugels, Jozef
    Katholieke Univ Leuven, Belgium.
    Upscaled Synthesis Protocol for Phase-Pure, Colloidally Stable MXenes with Long Shelf Lives2023In: Small Methods, E-ISSN 2366-9608Article in journal (Refereed)
    Abstract [en]

    MXenes are electrically conductive 2D transition metal carbides/nitrides obtained by the etching of nanolaminated MAX phase compounds, followed by exfoliation to single- or few-layered nanosheets. The mainstream chemical etching processes have evolved from pure hydrofluoric acid (HF) etching into the innovative "minimally intensive layer delamination" (MILD) route. Despite their current popularity and remarkable application potential, the scalability of MILD-produced MXenes remains unproven, excluding MXenes from industrial applications. This work proposes a "next-generation MILD" (NGMILD) synthesis protocol for phase-pure, colloidally stable MXenes that withstand long periods of dry storage. NGMILD incorporates the synergistic effects of a secondary salt, a richer lithium (Li) environment, and iterative alcohol-based washing to achieve high-purity MXenes, while improving etching efficiency, intercalation, and shelf life. Moreover, NGMILD comprises a sulfuric acid (H2SO4) post-treatment for the selective removal of the Li3AlF6 impurity that commonly persists in MILD-produced MXenes. This work demonstrates the upscaled NGMILD synthesis of (50 g) phase-pure Ti(3)C(2)Tz MXene clays with high extraction yields (>22%) of supernatant dispersions. Finally, NGMILD-produced MXene clays dry-stored for six months under ambient conditions experience minimal degradation, while retaining excellent redispersibility. Overall, the NGMILD protocol is a leap forward toward the industrial production of MXenes and their subsequent market deployment.

  • 39.
    He, Yixing
    et al.
    East China Univ Sci & Technol, Peoples R China; East China Univ Sci & Technol, Peoples R China.
    Zhu, Bin
    East China Univ Sci & Technol, Peoples R China; East China Univ Sci & Technol, Peoples R China.
    Li, Qizhao
    East China Univ Sci & Technol, Peoples R China; East China Univ Sci & Technol, Peoples R China.
    Baryshnikov, Glib
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Fang, Yu-Hui
    Peking Univ, Peoples R China.
    Li, Chengjie
    East China Univ Sci & Technol, Peoples R China; East China Univ Sci & Technol, Peoples R China.
    Sha, Feng
    East China Univ Sci & Technol, Peoples R China; East China Univ Sci & Technol, Peoples R China.
    Wu, Xin-Yan
    East China Univ Sci & Technol, Peoples R China; East China Univ Sci & Technol, Peoples R China.
    Wang, Bing-Wu
    Peking Univ, Peoples R China.
    agren, Hans
    Uppsala Univ, Sweden.
    Xie, Yongshu
    East China Univ Sci & Technol, Peoples R China; East China Univ Sci & Technol, Peoples R China.
    Chain Length Modulated Dimerization and Cyclization of Terminal Thienyl-Blocked Oligopyrranes2022In: Organic Letters, ISSN 1523-7060, E-ISSN 1523-7052, Vol. 24, no 29, p. 5428-5432Article in journal (Refereed)
    Abstract [en]

    Oxidation of thienyl-blocked bilane and pentapyrrane afforded chain length dependent products of the symmetric dimer D1 and the thienyloligopyrrin-appended pentaphyrin analogue P2, respectively, with the latter formed by simultaneous dimerization and cyclization. Coordination of D1 and P2 with Cu(II) afforded di-and monometallic complexes D1-Cu2 and P2 -Cu, respectively. These compounds exhibit distinct NIR absorption, with the absorption tail of D1-Cu2 extended to ca. 1900 nm despite its smaller conjugation framework than that of P2 -Cu.

  • 40.
    Hellwig, Raphael
    et al.
    Tech Univ Munich, Germany.
    Uphoff, Martin
    Tech Univ Munich, Germany.
    Paintner, Tobias
    Tech Univ Munich, Germany.
    Björk, Jonas
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Ruben, Mario
    KIT, Sweden; Univ Strasbourg, France.
    Klappenberger, Florian
    Tech Univ Munich, Germany.
    Barth, Johannes V.
    Tech Univ Munich, Germany.
    Ho-Mediated Alkyne Reactions at Low Temperatures on Ag(111)2018In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 24, no 60, p. 16126-16135Article in journal (Refereed)
    Abstract [en]

    Low-temperature approaches to catalytic conversions promise efficiency, selectivity, and sustainable processes. Control over certain coupling reactions can be obtained via the pre-positioning of reactive moieties by self-assembly. However, in the striving field of on-surface synthesis atomistic precision and control remains largely elusive, because the employed coupling reactions proceed at temperatures beyond the thermal stability of the supramolecular templates. Here, utilizing scanning tunneling microscopy, we demonstrate terminal alkyne on-surface reactions mediated by Ho atoms at a weakly reactive Ag(111) substrate at lowtemperatures. Density functional theory calculations confirm the catalytic activity of the involved adatoms. Pre-deposited Ho induces alkyne dehydrogenation starting at substrate temperatures as low as 100 K. Ho arriving at molecularly pre-covered surfaces held at 130 and 200 K produces covalent enyne-linked dimers and initiates cyclotrimerization, respectively. Statistical product analysis indicates a two-step pathway for the latter, whereby the enyne intermediates influence the distribution of the products. High chemoselectivity results from the absence of cyclotetramerization and diyne-forming homocoupling. Our analysis indicates that mainly the arriving Ho adatoms enable the coupling. These findings support the concept of dynamic heterogeneity by single-atom catalysts and pave the way for alternative means to control on-surface reactions.

  • 41.
    Holmqvist, Andreas
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry.
    Inhibitory effect on the proteasome regulatory subunit, RPN11/POH1, with the use of Capzimin-PROTAC to trigger apoptosis in cancer cells2020Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    Most patients diagnosed with cancer will receive systematic chemotherapy at some point during their illness, which almost always cause severe side effects for the patients such as, anemia, nausea and vomiting. The problems with today’s chemotherapy is not only that it cause severe side effects, but also that the cancer may develop resistance to the therapy, which is why the development of a new type of therapeutic agent is in dire need. The ubiquitin proteasome system (UPS) is a vital machinery for the cancer cells to maintain protein homeostasis, which also make them vulnerable to any disruption of this system. In recent years, a new technology has been developed that utilize the UPS by chemically bringing an E3 ubiquitin ligase into close proximity of a protein of choice and tagging the protein with ubiquitin for degradation. This technology is called proteolysis targeting chimera (PROTAC). In this project, we managed to theoretically develop a new type of cancer therapeutic agent, that utilize the PROTAC system together with the first-in-class proteasome regulatory subunit, POH1, inhibitor Capzimin as a warhead. By using Capzimin as a warhead it should be possible to polyubiquitinate POH1, and thus induce proteotoxic stress in the cancer cells to trigger apoptosis. This theoretically developed drug is therefore called Capzimin-PROTAC, which should be able to trigger apoptosis in cancer cells, and at the same time being relatively safe to normal healthy cells. 

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  • 42.
    Huang, Shoushuang
    et al.
    Shanghai Univ, Peoples R China.
    Gao, Chunyan
    Shanghai Univ, Peoples R China.
    Xin, Peijun
    Shanghai Univ, Peoples R China.
    Wang, Haitao
    Shanghai Univ, Peoples R China.
    Liu, Xiao
    Shanghai Univ, Peoples R China.
    Wu, Ye
    Shanghai Univ, Peoples R China.
    He, Qingquan
    Shanghai Univ, Peoples R China.
    Jiang, Yong
    Shanghai Univ, Peoples R China.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering. Shanghai Univ, Peoples R China.
    Chen, Zhiwen
    Shanghai Univ, Peoples R China.
    An advanced electrocatalyst for efficient synthesis of ammonia based on chemically coupled NiS@MoS2 heterostructured nanospheres2021In: Sustainable Energy & Fuels, E-ISSN 2398-4902, Vol. 5, no 10, p. 2640-2648Article in journal (Refereed)
    Abstract [en]

    The electrochemical reduction of nitrogen, as a sustainable alternative to the known Haber-Bosch process, possesses promising application prospects in the development of renewable energy storage systems. However, the yield of NH3 and Faraday efficiency are usually very low owing to the loss of active electrocatalysts and competitive hydrogen evolution reactions. Herein, uniform NiS@MoS2 core-shell microspheres are controllably prepared as a potential catalyst for an ambient electrocatalytic N-2 reduction reaction. The NiS@MoS2 microspheres possess highly active intrinsic, sufficient accessible active sites, high structural porosity, and convenient transport channels, consequently boosting the transmission of electrons and mass. Additionally, the interfacial interaction between NiS and MoS2 facilitates electron transfer, which further improves the catalytic activity by optimizing the free energies of reaction intermediates. As a result, the titled NiS@MoS2 shows excellent electrochemical activity and selectivity, capable of achieving a relatively high NH3 yield of 9.66 mu g h(-1) mg(cat)(-1) at -0.3 V (vs. the reversible hydrogen electrode, RHE) and a high FE of 14.8% at -0.1 V vs. RHE in 0.1 M Na2SO4. The work demonstrated here may open a new avenue for the rational design and synthesis of catalysts for the electrochemical synthesis of ammonia.

  • 43.
    Huang, Shoushuang
    et al.
    Shanghai Univ, Peoples R China.
    Jin, Zhiqiang
    Shanghai Univ, Peoples R China.
    Ning, Ping
    Shanghai Univ, Peoples R China.
    Gao, Chunyan
    Shanghai Univ, Peoples R China.
    Wu, Ye
    Shanghai Univ, Peoples R China.
    Liu, Xiao
    Shanghai Univ, Peoples R China.
    Xin, Peijun
    Shanghai Univ, Peoples R China.
    Chen, Zhangxian
    Hefei Univ Technol, Peoples R China.
    Jiang, Yong
    Shanghai Univ, Peoples R China.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering. Shanghai Univ, Peoples R China.
    Chen, Zhiwen
    Shanghai Univ, Peoples R China.
    Synergistically modulating electronic structure of NiS2 hierarchical architectures by phosphorus doping and sulfur-vacancies defect engineering enables efficient electrocatalytic water splitting2021In: Chemical Engineering Journal, ISSN 1385-8947, E-ISSN 1873-3212, Vol. 420, article id 127630Article in journal (Refereed)
    Abstract [en]

    The synergistic achievement of heteroatom doping, defect engineering and appropriate structural design is efficient to adjust and boost the catalytic performance of catalysts yet challenging. Herein, phosphorus (P)-doped NiS2 hierarchical architectures with sulfur vacancies are synthesized via a Prussian-blue-analogue-sacrificed strategy followed by a phosphidation process. By modulation of P doping and sulfur vacancies, the optimal catalyst manifests outstanding electrocatalytic activities, affording low overpotentials of 73 mV at 10 mA cm-2 for hydrogen evolution reaction (HER), and 255 mV at 20 mA cm-2 for oxygen evolution reaction (OER), respectively. Density functional theory calculations certify that the P dopant not only serves as the new active sites, but also activates the electrochemical activity of neighboring Ni and S sites. Moreover, the synergistic effect of P-doping and sulfur vacancies further improve electrochemical activities of HER and OER by optimizing the adsorption free energy of hydrogen (Delta GH*) and oxygen-containing intermediates (OH*, O* and OOH*), respectively. This finding provides a directive strategy to achieve efficient non-noble metal catalysts for energy conversion and storage.

  • 44.
    Hur, Deniz
    et al.
    Anadolu Univ, Turkey; Bionkit Co Ltd, Turkey.
    Say, Mehmet Girayhan
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering. Bionkit Co Ltd, Turkey.
    Diltemiz, Sibel E.
    Anadolu Univ, Turkey; Bionkit Co Ltd, Turkey.
    Duman, Fatma
    Anadolu Univ, Turkey.
    Ersoz, Arzu
    Anadolu Univ, Turkey; Bionkit Co Ltd, Turkey.
    Say, Ridvan
    Anadolu Univ, Turkey; Bionkit Co Ltd, Turkey.
    3D Micropatterned All-Flexible Microfluidic Platform for Microwave-Assisted Flow Organic Synthesis2018In: ChemPlusChem, E-ISSN 2192-6506, Vol. 83, no 1, p. 42-46Article in journal (Refereed)
    Abstract [en]

    A large-area, all-flexible, microwaveable polydimethoxysilane microfluidic reactor was fabricated by using a 3D printing system. The sacrificial microchannels were printed on polydimethoxysilane substrates by a direct ink writing method using water-soluble Pluronic F-127 ink and then encapsulated between polydimethoxysilane layers. The structure of micron-sized channels was analyzed by optical and electron microscopy techniques. The fabricated flexible microfluidic reactors were utilized for the acetylation of different amines under microwave irradiation to obtain acetamides in shorter reaction times and good yields by flow organic synthesis.

  • 45.
    Hussamadin, Ahmad
    Linköping University, Department of Physics, Chemistry and Biology.
    Multigram scale synthesis of synthetic cannabinoid metabolites2021Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    As of today, synthetic cannabinoids are one of the biggest groups of new psychoactive substances.These substances can be used as substitutes for the psychoactive drug cannabis, avoiding the legalrestrictions on cannabis. Furthermore, a variety of synthetic cannabinoids are synthesized with eithersignificant or very minor structural differences, making the detection of said novel drugs hard to keepup with and is therefore of great importance to have standards which help in the identification of theintake of the parent synthetic cannabinoid.

    In this project, several metabolites ofsynthetic cannabinoids with indole/indazole cores with differentside chains was synthesized. The general strategy used in this project was to N-alkylate the desiredcore followed by amide coupling with L-tert-leucine methyl ester or L-Valine methyl esterhydrochloride which resulted in 8 potential synthetic cannabinoid metabolites.

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    Multigram scale synthesis of synthetic cannabinoid metabolite_Ahmad Hussamadin
  • 46.
    Kalapos, Peter Pal
    et al.
    Res Ctr Nat Sci, Hungary.
    Mayer, Peter J.
    Res Ctr Nat Sci, Hungary; Univ Szeged, Hungary.
    Gazdag, Tamas
    Res Ctr Nat Sci, Hungary; Eotvos Lorand Univ, Hungary.
    Demeter, Attila
    Res Ctr Nat Sci, Hungary.
    Oruganti, Baswanth
    Linnaeus Univ, Sweden.
    Durbeej, Bo
    Linköping University, Department of Physics, Chemistry and Biology, Bioinformatics. Linköping University, Faculty of Science & Engineering.
    London, Gabor
    Res Ctr Nat Sci, Hungary.
    Photoswitching of Local (Anti)Aromaticity in Biphenylene-Based Diarylethene Molecular Switches2022In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 87, no 15, p. 9532-9542Article in journal (Refereed)
    Abstract [en]

    Photoinduced tuning of (anti)aromaticity and associated molecular properties is currently in the focus of attention for both tailoring photochemical reactivity and designing new materials. Here, we report on the synthesis and spectroscopic characterization of diarylethene-based molecular switches embedded in a biphenylene structure composed of rings with different levels of local (anti)aromaticity. We show that it is possible to modulate and control the (anti)aromatic character of each ring through reversible photoswitching of the aryl units of the system between open and closed forms. Remarkably, it is shown that the irreversible formation of an annulated bis(dihydro-thiopyran) side-product that hampers the photoswitching can be efficiently suppressed when the aryl core formed by thienyl groups in one switch is replaced by thiazolyl groups in another.

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    fulltext
  • 47.
    Klingstedt, Therése
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry. Linköping University, The Institute of Technology.
    Åslund, Andreas
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry. Linköping University, The Institute of Technology.
    Simon, Rozalyn
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry. Linköping University, The Institute of Technology.
    Johansson, Leif B. G.
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry. Linköping University, The Institute of Technology.
    Mason, Jeffrey
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry. Linköping University, The Institute of Technology.
    Nyström, Sofie
    Linköping University, Department of Physics, Chemistry and Biology, Protein Science. Linköping University, The Institute of Technology.
    Hammarström, Per
    Linköping University, Department of Physics, Chemistry and Biology, Protein Science. Linköping University, The Institute of Technology.
    Nilsson, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry. Linköping University, The Institute of Technology.
    Synthesis of a library of oligothiophenes and their utilization as fluorescent ligands for spectral assignment of protein aggregates2011In: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 9, no 24, p. 8356-8370Article in journal (Refereed)
    Abstract [en]

    Molecular probes for selective identification of protein aggregates are important to advance our understanding of the molecular pathogenesis underlying protein aggregation diseases. Here we report the chemical design of a library of anionic luminescent conjugated oligothiophenes (LCOs), which can be utilized as ligands for detection of protein aggregates. Certain molecular requirements were shown to be necessary for detecting (i) early non-thioflavinophilic protein assemblies of A beta 1-42 and insulin preceding the formation of amyloid fibrils and (ii) for obtaining distinct spectral signatures of the two main pathological hallmarks observed in human Alzheimers diease brain tissue (A beta plaques and neurofibrillary tangles). Our findings suggest that a superior anionic LCO-based ligand should have a backbone consisting of five to seven thiophene units and carboxyl groups extending the conjugated thiophene backbone. Such LCOs will be highly useful for studying the underlying molecular events of protein aggregation diseases and could also be utilized for the development of novel diagnostic tools for these diseases.

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  • 48.
    Kulyk, Dmytro S.
    et al.
    Ohio State Univ, OH 43210 USA.
    Baryshnikov, Glib
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Damale, Purva S.
    Ohio State Univ, OH 43210 USA.
    Maher, Simon
    Univ Liverpool, England.
    Badu-Tawiah, Abraham K.
    Ohio State Univ, OH 43210 USA.
    Charge inversion under plasma-nanodroplet reaction conditions excludes Fischer esterification for unsaturated fatty acids: a chemical approach for type II isobaric overlap2023In: Chemical Science, ISSN 2041-6520, E-ISSN 2041-6539Article in journal (Refereed)
    Abstract [en]

    Direct infusion ionization methods provide the highest throughput strategy for mass spectrometry (MS) analysis of low-volume samples. But the trade-off includes matrix effects, which can significantly reduce analytical performance. Herein, we present a novel chemical approach to tackle a special type of matrix effect, namely type II isobaric overlap. We focus on detailed investigation of a nanodroplet-based esterification chemistry for differentiating isotopologue [M + 2] signal due to unsaturated fatty acid (FA) from the monoisotopic signal from a saturated FA. The method developed involves the online fusion of nonthermal plasma with charged nanodroplets, enabling selective esterification of saturated FAs. We discovered that unsaturated FAs undergo spontaneous intramolecular reaction via a novel mechanism based on a carbocation intermediate to afford a protonated lactone moiety (resonance stabilized cyclic carbonium ion), whose mass is the same as the original protonated unsaturated FA. Therefore, the monoisotopic signal from any saturated FA can be selectively shifted away from the mass-to-charge position where the isobaric interference occurs to enable effective characterization by MS. The mechanism governing the spontaneous intramolecular reactions for unsaturated FAs was validated with DFT calculations, experimentation with standards, and isotope labeling. This novel insight achieved via the ultrafast plasma-nanodroplet reaction environment provides a potentially useful synthetic pathway to achieve catalyst-free lactone preparation. Analytically, we believe the performance of direct infusion MS can be greatly enhanced by combining our approach with prior sample enrichment steps for applications in biomedicine and food safety. Also, combination with portable mass spectrometers can improve the efficiency of field studies since front-end separation is not possible under such conditions. The fusion of nonthermal plasma with charged nanodroplets enables selective esterification of saturated fatty acids, which is utilized to overcome challenges associated with type II isobaric overlap in direct infusion mass spectrometry.

  • 49.
    Lai, Kwok Kei
    et al.
    Hong Kong University of Science and Technology, Clear Water Bay, P. R. China .
    Renneberg, Reinhard
    Hong Kong University of Science and Technology, Clear Water Bay, P. R. China .
    Mak, Wing Cheung
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    High efficiency single-step biomaterial-based microparticle fabrication via template-directed supramolecular coordination chemistry2016In: Green Chemistry, ISSN 1463-9262, E-ISSN 1463-9270, Vol. 18, no 6, p. 1715-1723Article in journal (Refereed)
    Abstract [en]

    Biomaterial-based microparticles have attracted much attention for medical and biological applications such as pharmaceutics, bioseparation and cosmetics. Emerging technologies enable versatile and facile fabrication of microparticles, with key features being purity, precise size control, mild preparation conditions and minimal processing. Here, an innovative approach combining template synthesis, biomolecule assembly and partial-purification within a single step for high efficiency fabrication of pure biomaterial-based microparticles is reported. This concept is based on facile co-precipitation of biomolecules within CaCO3 templates and simultaneous crosslinking of entrapped biomolecules via Ca2+ driven supramolecular coordination chemistry, followed by template removal. Carbohydrate (alginate) and proteins (casein and fresh milk) are used as models of biomolecules. The process driven by selective crosslinking automatically excludes non-specific materials from the template and thus provides the additional function of partial-purification, as demonstrated using highly complexed fresh milk. This green approach to fabrication of biomaterial-based microparticles offers three critical advantages (i) mild conditions to preserve the chemical and secondary structures of biomolecules; (ii) single processing step to facilitate scale-up production; and (iii) partial-purification without the need for upstream raw material purification. This innovative approach not only addresses fundamental issues in fabrication techniques, but also marks progress in energy and environmental conservation during manufacturing processes.

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  • 50.
    Lantz, Linda
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Synthesis of donor–acceptor–donor thiophene based ligands that can be utilized for optical assignment of pathological targets2022Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Thiophene based ligands represent a class of molecular reporters proven superior in discerning pathological targets involved in neurodegenerative diseases, as well as bacterial infection. By fluorometric detection that depends on the milieu surrounding the ligand these biological processes can be studied with fluorescence spectroscopy and hyper-spectral confocal microscopy. The binding of a thiophene-based ligand to a biological target can entail specific fluorescent read-out through the conformation-sensitive ligand. Thus, the photo-physical properties of these molecules and the optical connection of binding make them valuable tools in the study of pathological events. As optical detection of pathological phenomena can be realized through several fluorescence parameters, including changes in fluorescent intensity, wavelength shifts, energy transfer, or emission lifetime, molecular studies of pathological targets in several biological systems have been realized by employing thiophene-based ligands. For instance, utilization of conjugated polydisperse and monodisperse thiophene-based molecules has in several studies demonstrated detection of disease associated protein aggregates in vitro, ex vivo and in vivo

    My doctoral studies have included the synthesis and characterization of thiophene based donor-acceptor-donor (D–A–D) molecules and evaluation of how changes in side-chain positions, molecular length and number of negatively charged carboxylates impact interaction with biological targets. This thesis describes the utilization of the D–A–D molecules as fluorescent ligands for protein aggregates associated with Alzheimer’s disease and optical assignment of specific bacteria. The design and synthesis of these novel D–A–D thiophene-based fluorophores, with alterations in back bone, distribution of side chains and negatively charged groups, have generated novel insights regarding the ligands chemical structure on ligand performance, by the assessment of binding mode of the respective ligand to distinct pathological entities. Furthermore, the D–A–D molecules hold alternative photo-physical properties compared to thiophene-based ligand and these optical properties of the ligands have been employed to provide new insights in questions regarding protein aggregate polymorphism in Alzheimer’s disease. Overall, by organic synthesis we have fine-tuned the properties of thiophene-based D-A-D molecules and evaluated how modifications affect interactions with distinct biological, pathological targets and we foresee that D–A–D thiophene-based ligands will expand the toolbox for studying pathological targets in neurodegenerative diseases, as well as bacterial infection. 

    List of papers
    1. Synthesis and Characterization of Thiophene-based Donor-Acceptor-Donor Heptameric Ligands for Spectral Assignment of Polymorphic Amyloid-beta Deposits
    Open this publication in new window or tab >>Synthesis and Characterization of Thiophene-based Donor-Acceptor-Donor Heptameric Ligands for Spectral Assignment of Polymorphic Amyloid-beta Deposits
    2020 (English)In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 26, no 33, p. 7425-7432Article in journal (Refereed) Published
    Abstract [en]

    Protein deposits are associated with many devastating diseases and fluorescent ligands able to visualize these pathological entities are essential. Here, we report the synthesis of thiophene-based donor-acceptor-donor heptameric ligands that can be utilized for spectral assignment of distinct amyloid-beta (A beta) aggregates, one of the pathological hallmarks in Alzheimers disease. The ability of the ligands to selectively distinguish A beta deposits was abolished when the chemical composition of the ligands was altered. Our findings provide the structural and functional basis for the development of new fluorescent ligands that can distinguish between aggregated proteinaceous species consisting of the same peptide or protein. In addition, such ligands might aid in interpreting the potential role of polymorphic A beta deposits in the pathogenesis of Alzheimers disease.

    Place, publisher, year, edition, pages
    WILEY-V C H VERLAG GMBH, 2020
    Keywords
    Alzheimers disease; fluorescence; luminescent conjugated oligothiophenes; protein aggregates; beta-amyloid
    National Category
    Biochemistry and Molecular Biology
    Identifiers
    urn:nbn:se:liu:diva-166174 (URN)10.1002/chem.201905612 (DOI)000532854400001 ()32022335 (PubMedID)
    Note

    Funding Agencies|Swedish Research CouncilSwedish Research Council [2016-00748]; Erling Persson foundation

    Available from: 2020-06-09 Created: 2020-06-09 Last updated: 2022-11-24
    2. Structural Properties Dictating Selective Optotracer Detection of Staphylococcus aureus
    Open this publication in new window or tab >>Structural Properties Dictating Selective Optotracer Detection of Staphylococcus aureus
    Show others...
    2022 (English)In: ChemBioChem (Print), ISSN 1439-4227, E-ISSN 1439-7633, Vol. 23, no 11, article id e202100684Article in journal (Refereed) Published
    Abstract [en]

    Optotracers are conformation-sensitive fluorescent tracer molecules that detect peptide- and carbohydrate-based biopolymers. Their binding to bacterial cell walls allows selective detection and visualisation of Staphylococcus aureus (S. aureus). Here, we investigated the structural properties providing optimal detection of S. aureus. We quantified spectral shifts and fluorescence intensity in mixes of bacteria and optotracers, using automatic peak analysis, cross-correlation, and area-under-curve analysis. We found that the length of the conjugated backbone and the number of charged groups, but not their distribution, are important factors for selective detection of S. aureus. The photophysical properties of optotracers were greatly improved by incorporating a donor-acceptor-donor (D-A-D)-type motif in the conjugated backbone. With significantly reduced background and binding-induced on-switch of fluorescence, these optotracers enabled real-time recordings of S. aureus growth. Collectively, this demonstrates that chemical structure and photophysics are key tunable characteristics in the development of optotracers for selective detection of bacterial species.

    Place, publisher, year, edition, pages
    Wiley-V C H Verlag GMBH, 2022
    Keywords
    bacterial detection; fluorescence microscopy; fluorescence spectroscopy; optotracers; real-time monitoring
    National Category
    Analytical Chemistry
    Identifiers
    urn:nbn:se:liu:diva-184429 (URN)10.1002/cbic.202100684 (DOI)000776536900001 ()35298076 (PubMedID)
    Note

    Funding Agencies|AIMES -Center for the Advancement of Integrated Medical and Engineering Sciences at Karolinska Institutet [1-249/2019]; KTH Royal Institute of Technology [VF-2019-0110]; Erling-Persson Family Foundation [4-1784/2016]; Swedish Research CouncilSwedish Research CouncilEuropean Commission [00748]; Swedish Foundation for Strategic ResearchSwedish Foundation for Strategic Research [SB12-00347]; Getinge AB [4-1599/2018]

    Available from: 2022-04-21 Created: 2022-04-21 Last updated: 2023-04-06Bibliographically approved
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