Počet záznamů: 1
Ultrafast excited-state dynamics of isocytosine
- 1.
SYSNO ASEP 0471961 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název Ultrafast excited-state dynamics of isocytosine Tvůrce(i) Szabla, Rafal (BFU-R) ORCID
Gora, R.W. (PL)
Šponer, Jiří (BFU-R) RID, ORCIDCelkový počet autorů 3 Zdroj.dok. Physical Chemistry Chemical Physics. - : Royal Society of Chemistry - ISSN 1463-9076
Roč. 18, č. 30 (2016), s. 20208-20218Poč.str. 11 s. Forma vydání Tištěná - P Jazyk dok. eng - angličtina Země vyd. GB - Velká Británie Klíč. slova perturbation-theory ; relaxation mechanisms Vědní obor RIV BO - Biofyzika CEP GA14-12010S GA ČR - Grantová agentura ČR Institucionální podpora BFU-R - RVO:68081707 UT WOS 000381428600022 DOI https://doi.org/10.1039/c6cp01391k Anotace The alternative nucleobase isocytosine has long been considered as a plausible component of hypothetical primordial informational polymers. To examine this hypothesis we investigated the excited-state dynamics of the two most abundant forms of isocytosine in the gas phase (keto and enol). Our surface-hopping nonadiabatic molecular dynamics simulations employing the algebraic diagrammatic construction to the second order [ADC(2)] method for the electronic structure calculations suggest that both tautomers undergo efficient radiationless deactivation to the electronic ground state with time constants which amount to tau(keto) = 182 fs and tau(enol) = 533 fs. The dominant photorelaxation pathways correspond to ring-puckering (pi pi* surface) and C = O stretching/N-H tilting (n pi* surface) for the enol and keto forms respectively. Based on these findings, we infer that isocytosine is a relatively photostable compound in the gas phase and in these terms resembles biologically relevant nucleobases. The estimated S-1> T-1 intersystem crossing rate constant of 8.02 x 10(10) s(-1) suggests that triplet states might also play an important role in the overall excited-state dynamics of the keto tautomer. The reliability of ADC(2)-based surface-hopping molecular dynamics simulations was tested against multireference quantum-chemical calculations and the potential limitations of the employed ADC(2) approach are briefly discussed. Pracoviště Biofyzikální ústav Kontakt Jana Poláková, polakova@ibp.cz, Tel.: 541 517 244 Rok sběru 2017
Počet záznamů: 1