Ultrafast excited-state dynamics of isocytosine

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081707%3A_____%2F16%3A00471961" target="_blank" >RIV/68081707:_____/16:00471961 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216224:14740/16:00091111

Výsledek na webu

<a href="http://dx.doi.org/10.1039/c6cp01391k" target="_blank" >http://dx.doi.org/10.1039/c6cp01391k</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/c6cp01391k" target="_blank" >10.1039/c6cp01391k</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Ultrafast excited-state dynamics of isocytosine

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

Ultrafast excited-state dynamics of isocytosine

Popis výsledku anglicky

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.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

BO - Biofyzika

OECD FORD obor

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Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2016

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physical Chemistry Chemical Physics

ISSN

1463-9076

e-ISSN

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Svazek periodika

18

Číslo periodika v rámci svazku

30

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

11

Strana od-do

20208-20218

Kód UT WoS článku

000381428600022

EID výsledku v databázi Scopus

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