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 |