Structure of radical cations of saturated heterocyclic compounds with two heteroatoms as studied by electron paramagnetic resonance, electron-nuclear double resonance, and density functional theory calculations
2005 (English)In: Journal of Physical Chemistry A, ISSN 1089-5639, Vol. 109, no 28, 6166-6173 p.Article in journal (Refereed) Published
The radical cations of piperazine, morpholine, thiomorpholine, and thioxane were investigated by electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) spectroscopy in a solid Freon matrix. Optimized geometry and magnetic parameters of the radical cations were calculated using a density functional theory (DFT)/Perdew-Burke-Ernzerhof (PBE) method. Both experimental and theoretical results suggest that all the studied species adopt chair (or distorted chair) conformations. No evidence for the boat conformers with intramolecular σ*-bonding between heteroatoms were obtained. In the cases of morpholine and thioxane, the oxygen atoms are characterized by relatively small spin populations, whereas a major part of spin density is located at N and S atoms, respectively. The thiomorpholine radical cation exhibits nearly equal spin population of N and S atoms. In most cases (except for thioxane), the calculated magnetic parameters agree with the experimental data reasonably well. © 2005 American Chemical Society.
Place, publisher, year, edition, pages
2005. Vol. 109, no 28, 6166-6173 p.
IdentifiersURN: urn:nbn:se:liu:diva-33715DOI: 10.1021/jp051440lLocal ID: 19756OAI: oai:DiVA.org:liu-33715DiVA: diva2:254538