Solvent effects on optically detected magnetic resonance in triplet spin labels
2004 (English)In: Theoretical Chemistry accounts, ISSN 1432-881X, E-ISSN 1432-2234, Vol. 111, no 2-6, 168-175 p.Article in journal (Refereed) Published
We have calculated solvent effects on the zero-field splitting (ZFS) constants induced by electron spin-spin coupling (SSC) in the low-lying triplet states of azaaromatic molecules in solutions using multiconfiguration self-consistent-field wave functions and the polarizable continuum model. The second-order spin-orbit coupling (SOC) contribution to the splitting of the (3)pipi(*) states is found to be almost negligible, and the calculations therefore provide a good estimate of the ZFS parameters and their solvent dependence based only on the electron spin-spin coupling expectation values. The correlation between the shift in the ZFS and the phosphorescence frequency that has been observed in optically detected magnetic resonance experiments in low-temperature glasses is supported by our direct SSC calculations without taking SOC into account. This makes it possible to distinguish between the two theories that earlier were proposed to explain the inhomogeneous broadening of triplet state spectra, and discard the one that is exclusively based on the SOC-induced mixing of the singlet and triplet states.
Place, publisher, year, edition, pages
2004. Vol. 111, no 2-6, 168-175 p.
zero-field splitting, solvent effects, triplet spin label, optically detected magnetic resonance, electron spin-spin coupling, field splitting parameters, polarizable continuum model, g-tensor calculations, gaussian-basis sets, anisotropic dielectrics, ionic-solutions, dna complexes, state, phosphorescence, molecules
IdentifiersURN: urn:nbn:se:kth:diva-23277DOI: 10.1007/s00214-003-0532-5ISI: 000220424700014ScopusID: 2-s2.0-2442473770OAI: oai:DiVA.org:kth-23277DiVA: diva2:341975
QC 20100525 QC 201110312010-08-102010-08-102012-01-20Bibliographically approved