Photodynamics simulations of thymine: relaxation into the first excited singlet state

0334356 - ÚOCHB 2010 RIV US eng J - Článek v odborném periodiku
Szymczak, J. J. - Barbatti, M. - Soo Hoo, J. T. - Adkins, J. A. - Windus, T. L. - Nachtigallová, Dana - Lischka, Hans
Photodynamics simulations of thymine: relaxation into the first excited singlet state.
Journal of Physical Chemistry A. Roč. 113, č. 45 (2009), s. 12686-12693. ISSN 1089-5639. E-ISSN 1520-5215
Grant CEP: GA MŠMT LC512
Grant ostatní: ANSF(US) OISE-0730114
Výzkumný záměr: CEZ:AV0Z40550506
Klíčová slova: nucleic acid bases * nonadiabatic dynamics simulations * relaxation mechanism
Kód oboru RIV: CF - Fyzikální chemie a teoretická chemie
Impakt faktor: 2.899, rok: 2009

Ab initio nonadiabatic dynamics simulations are reported for thymine with focus on the S2 to S1 deactivation using the state-averaged CASSCF method. The photodynamical process starts with a fast (<100 fs) planar relaxation from the S2 pipi* state into the piOpi* minimum of the S2 state. The time in reaching the S2/S1 intersections, through which thymine can deactivate to S1, is delayed by both the change in character between the states as well as the flatness of the S2 surface. The present dynamics simulations show that not only the piOpi* S2 trapping but also the trapping in the npi* S1 minimum contribute to the elongation of the excited state lifetime of thymine.
Trvalý link: http://hdl.handle.net/11104/0005588