標題: | Ultrafast intersystem crossing for nitrophenols: ab initio nonadiabatic molecular dynamics simulation |
作者: | Xu, Chao Gu, Feng Long Zhu, Chaoyuan 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 |
公開日期: | 28-二月-2018 |
摘要: | Ultrafast intersystem crossing mechanisms for two p- and m-nitrophenol groups (PNP and MNP) have been investigated using ab initio nonadiabatic molecular dynamics simulations at the 6SA-CASSCF level of theory. Trajectory surface hopping simulation has been performed within an intersystem crossing network constructed from two low-lying singlets (S-0 and S-1) and two low-lying triplets (T-1 and T-2). It is found that the dominant relaxation S-1 -> T-2 pathway accounts for 65.4% (85.0%) of the quantum yield with a time constant of 13.4 fs (22 fs) and the S-1 -> T-2 -> S-0 pathway accounts for 33.1% (13.5%) with a time constant of 275 fs ( 375 fs) for PNP ( MNP). In comparison with the previously studied excited-state proton transfer process for ONP, the dominant relaxation S-1 -> T-2 -> T-1 pathway accounts for 49.3% with a time constant of 40 fs and the S-1 -> T-2 -> T-1 -> S-0 pathway accounts for 47.5% with a time constant of 300 fs. The relaxation mechanisms and electronic structures of the intersystem crossings are in close relation with the relative motion between the torsion motions of the nitro-group and the hydroxyl group. The present simulation provides new physical insight for understanding ultrafast photochemical intersystem crossing dynamics. |
URI: | http://dx.doi.org/10.1039/c7cp08601f http://hdl.handle.net/11536/144657 |
ISSN: | 1463-9076 |
DOI: | 10.1039/c7cp08601f |
期刊: | PHYSICAL CHEMISTRY CHEMICAL PHYSICS |
Volume: | 20 |
起始頁: | 5606 |
結束頁: | 5616 |
顯示於類別: | 期刊論文 |