liu.seSearch for publications in DiVA
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Weakly coupled proton interactions in the malonic acid radical: Single crystal ENDOR analysis and EPR simulation at microwave saturation
Univ Oslo, Dept Phys, N-0316 Oslo, Norway Linkoping Univ, Dept Phys & Measurement Tech, S-58183 Linkoping, Sweden Chim Phys Lab, F-75005 Paris, France.
Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Chemical Physics .
Univ Oslo, Dept Phys, N-0316 Oslo, Norway Linkoping Univ, Dept Phys & Measurement Tech, S-58183 Linkoping, Sweden Chim Phys Lab, F-75005 Paris, France.
Univ Oslo, Dept Phys, N-0316 Oslo, Norway Linkoping Univ, Dept Phys & Measurement Tech, S-58183 Linkoping, Sweden Chim Phys Lab, F-75005 Paris, France.
2000 (English)In: Journal of Physical Chemistry A, ISSN 1089-5639, Vol. 104, no 27, 6362-6371 p.Article in journal (Refereed) Published
Abstract [en]

The alpha-proton hyperfine coupling observed by electron paramagnetic resonance (EPR) spectroscopy on the radical (CH)-C-.(COOH)(2) in irradiated crystals of malonic acid, CH2(COOH)(2), has served as a standard against which hundreds of observations of similar couplings have been held and scaled. The major doublet of the malonic acid radical is accompanied by less intense "forbidden" (f) alpha-proton transitions and "spin-flip" (s) transitions due to weakly interacting protons. Both s and f transition lines exhibit microwave power saturation behaviors different from that of the major doublet. At high microwave power, the prominence of these s and f lines may be misinterpreted as originating from different radical species. Computer simulations could help distinguish between the different cases, but no computer simulation programs taking into account the microwave power saturation case are commonly available. On the basis of classical line-shape theory, an algorithm describing the microwave power dependence of an EPR line shape has been developed and implemented in an existing simulation program. To test this new program, malonic acid was selected because of the simplicity of its EPR spectra. However, sufficiently detailed information about the hyperfine coupling parameters for a satisfactory simulation of the room-temperature data (including s and f lines) was not available in the literature. Therefore, a detailed room-temperature EPR/ENDOR study on a single crystal of malonic acid was performed. In addition to the major cc-proton coupling, seven weaker proton interactions have been characterized and partly identified. Simulations under nonsaturating conditions reproduce very well all features of the experimental EPR spectra. Simulations under saturating conditions similarly reproduce the power-dependent EPR spectra and yield information about the relaxation behavior of the radical system, which is amenable to verification using other spin-resonance methods.

Place, publisher, year, edition, pages
2000. Vol. 104, no 27, 6362-6371 p.
National Category
Engineering and Technology
Identifiers
URN: urn:nbn:se:liu:diva-49670OAI: oai:DiVA.org:liu-49670DiVA: diva2:270566
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2011-01-14

Open Access in DiVA

No full text

Authority records BETA

Lund, Anders

Search in DiVA

By author/editor
Lund, Anders
By organisation
The Institute of TechnologyChemical Physics
In the same journal
Journal of Physical Chemistry A
Engineering and Technology

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 50 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf