標題: Ultrafast nonradiative transition pathways in photo-excited pyrazine: Ab initio analysis of time-resolved vacuum ultraviolet photoelectron spectrum
作者: Mignolet, Benoit
Kanno, Manabu
Shimakura, Noriyuki
Koseki, Shiro
Remacle, Francoise
Kono, Hirohiko
Fujimura, Yuichi
應用化學系
應用化學系分子科學碩博班
Department of Applied Chemistry
Institute of Molecular science
關鍵字: Pyrazine;Internal conversion;Dark states;Vacuum ultraviolet laser;Photoelectron spectrum
公開日期: 14-十一月-2018
摘要: The internal conversion of photo-excited pyrazine, which occurs rapidly on a time scale of about 20 fs, has long been considered to proceed via a conical intersection between the optically bright S-2 (B-1(2u), pi pi*) and dark S-1 (B-1(3u), n pi*) states. Since 2008, several theoretical studies have raised the possibility that other dark states S-3 ((1)A(u), n pi*) and S-4 (B-1(2g), n pi*) may participate dominantly in the early stage of the nonradiative decay of S-2. To clarify this issue, being motivated by the recent pump-probe experiment by Horio et al. [J. Chem. Phys. 145 (2016) 044306], we calculated vacuum ultraviolet photoelectron spectra for ionization from each of the four excited states. Comparison was made with the measured time-resolved photoelectron spectrum exhibiting a temporally varying multi-band structure. We confirmed no contribution of S-3 or S-4 and thus the validity of the conventional two-state (S-2 -> S-1) picture for ultrafast nonradiative transition in pyrazine.
URI: http://dx.doi.org/10.1016/j.chemphys.2018.07.015
http://hdl.handle.net/11536/148640
ISSN: 0301-0104
DOI: 10.1016/j.chemphys.2018.07.015
期刊: CHEMICAL PHYSICS
Volume: 515
起始頁: 704
結束頁: 709
顯示於類別:期刊論文