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-Feb-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
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