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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

On the population of triplet states of 2-seleno-thymine

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Author(s):
Valverde, Danillo [1] ; Mai, Sebastian [2, 3] ; Sanches de Araujo, Adalberto Vasconcelos [4] ; Canuto, Sylvio [1] ; Gonzalez, Leticia [2] ; Borin, Antonio Carlos [4]
Total Authors: 6
Affiliation:
[1] Univ Sao Paulo, Inst Phys, Rua Matao 1371, BR-05508090 Sao Paulo, SP - Brazil
[2] Univ Vienna, Fac Chem, Inst Theoret Chem, Wahringer Str 17, A-1090 Vienna - Austria
[3] Vienna Univ Technol, Photon Inst, Gusshausstr 27-29, A-1040 Vienna - Austria
[4] Univ Sao Paulo, Dept Fundamental Chem, Inst Chem, Av Prof Lineu Prestes 748, BR-05508000 Sao Paulo, SP - Brazil
Total Affiliations: 4
Document type: Journal article
Source: Physical Chemistry Chemical Physics; v. 23, n. 9, p. 5447-5454, MAR 7 2021.
Web of Science Citations: 0
Abstract

The population and depopulation mechanisms leading to the lowest-lying triplet states of 2-Se-Thymine were studied at the MS-CASPT2/cc-pVDZ level of theory. Several critical points on different potential energy hypersurfaces were optimized, including minima, conical intersections, and singlet-triplet crossings. The accessibility of all relevant regions on the potential energy hypersurfaces was investigated by means of minimum energy paths and linear interpolation in internal coordinates techniques. Our analysis indicates that, after the population of the bright S-2 state in the Franck-Condon region, the first photochemical event is a barrierless evolution towards one of its two minima. After that, three viable photophysical deactivation paths can take place. In one of them, the population in the S-2 state is transferred to the T-2 state via intersystem crossing and subsequently to the T-1 state by internal conversion. Alternatively, the S-1 state could be accessed by internal conversion through two distinct conical intersections with S-2 state followed by singlet-triplet crossing with the T-2 state. The absence of a second minimum on the T-1 state and a small energy barrier on pathway along the potential energy surface towards the ground state from the lowest triplet state are attributed as potential reasons to explain why the lifetime of the triplet state of 2-Se-Thymine might be reduced in comparison with its thio-analogue. (AU)

FAPESP's process: 18/19454-5 - Structure and Photochemistry of Fluorescent Nucleobaseas and Metal Mediated Base Pairs
Grantee:Antonio Carlos Borin
Support type: Regular Research Grants
FAPESP's process: 14/50983-3 - INCT 2014: complex fluids
Grantee:Antonio Martins Figueiredo Neto
Support type: Research Projects - Thematic Grants
FAPESP's process: 19/04413-4 - Photophysical properties of heavy atom modified nucleobases
Grantee:Danillo Pires Valverde
Support type: Scholarships abroad - Research Internship - Doctorate
FAPESP's process: 17/02612-4 - Dynamics of excited states and spectroscopic properties of natural and synthetic DNA and RNA derivatives in solvent environment
Grantee:Danillo Pires Valverde
Support type: Scholarships in Brazil - Doctorate