Inter-Excited State Phosphorescence in the Four-Component Relativistic Kohn–Sham Approximation: A Case Study on Lumiflavin
2015 (English)In: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 119, no 49, 11911-11921 p.Article in journal (Refereed) Published
Electronic transitions from one excited state to another excited state of different spin symmetry play important roles in many biochemical reactions. Although recent years have seen much progress in the elucidation of nonradiative (intersystem crossing) relaxation mechanisms for such transitions, there is presently a scarcity of data available to assess whether also radiative (phosphorescence) mechanisms are relevant for these processes. Here, we demonstrate that the well-established ability of quantum chemical methods to describe intersystem crossing events between excited states, can be supplemented by the ability to also describe inter-excited state phosphorescence. Specifically, performing four-component relativistic time-dependent density functional theory calculations, we obtain rate constants for the radiative transitions from the absorbing 1(πHπL*) singlet state of lumiflavin to the 3(πHπL*), 3(nN2πL*) and 3(πH–1πL*) triplet states, and subsequently compare these results with rate constants calculated for the corresponding nonradiative transitions. Thereby, it is found that the radiative rate constants for these particular transitions are typically two to five orders of magnitude smaller than the nonradiative ones.
Place, publisher, year, edition, pages
American Chemical Society (ACS), 2015. Vol. 119, no 49, 11911-11921 p.
Inter-excited state transition dipole moments, Radiative transitions, Nonradiative transitions, Response theory, Time-dependent density functional theory, Flavin chromophores
Chemical Sciences Physical Chemistry
IdentifiersURN: urn:nbn:se:liu:diva-122743DOI: 10.1021/acs.jpca.5b08908ISI: 000366339400016OAI: oai:DiVA.org:liu-122743DiVA: diva2:872563
Vid tiden för disputation förelåg publikationen som manuskript2015-11-192015-11-192016-01-11Bibliographically approved