Does Stacking Restrain the Photodynamics of Individual Nucleobases?

0346458 - ÚOCHB 2011 RIV US eng J - Journal Article
Nachtigallová, Dana - Zelený, T. - Ruckenbauer, M. - Müller, T. - Barbatti, M. - Hobza, Pavel - Lischka, Hans
Does Stacking Restrain the Photodynamics of Individual Nucleobases?
Journal of the American Chemical Society. Roč. 132, č. 24 (2010), s. 8261-8263. ISSN 0002-7863. E-ISSN 1520-5126
R&D Projects: GA MŠMT LC512
Grant - others:GA ČR(CZ) GD203/09/H046
Program: GD
Institutional research plan: CEZ:AV0Z40550506
Keywords : excited states dynamics * nucleobases * QM/MM method
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 9.019, year: 2010

Nonadiabatic photodynamical simulations of 4-aminopyrimidine (4-APy) used as a model for adenine were performed by embedding it between two stacking methyl-guanine (mGua) molecules to determine the effect of spatial restrictions on the ultrafast photodeactivation mechanism of this nucleobase. During the dynamics the formation of a significant fraction of intrastrand hydrogen bonding from 4-APy to mGua above and below is observed. These findings show that this type of hydrogen bond may play an important role for the photodynamics within one DNA strand and that it should be of interest even in irregular segments of double stranded nucleic acids structures. The relaxation mechanism of internal conversion to the ground state is dominated by ring puckering, and an overall elongation of the lifetime by -20% as compared to the isolated 4-APy is computed.
Permanent Link: http://hdl.handle.net/11104/0187482