Premium
Factors Affecting the Branching Ratio of Photodissociation: Thiophenol Studied through Quantum Wavepacket Dynamics
Author(s) -
An Heesun,
Choi Heechol,
Lee Yoon Sup,
Baeck Kyoung Koo
Publication year - 2015
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201500060
Subject(s) - conical intersection , excited state , photodissociation , chemistry , branching fraction , thiophenol , wave packet , torsion (gastropod) , quantum , excitation , atomic physics , molecular physics , photochemistry , physics , quantum mechanics , medicine , surgery , medicinal chemistry
The photodissociation dynamics of thiophenol (PhSH) excited to the 1 1 ππ* state was investigated by time‐dependent quantum wavepacket propagation within two‐dimensional (2D) space consisting of the SH bond and SH torsion. We systematically studied the dependence of the branching ratio ${\left( {{{{\rm{\tilde A}}} \mathord{\left/ {\vphantom {{{\rm{\tilde A}}} {{\rm{\tilde X \right. \kern-\nulldelimiterspace} {{\rm{\tilde X \right)}$ between the two electronic states of the phenylthiyl radical (PhS . ) on several factors of the 2D potential energy surfaces (PESs). The effect of a reduced initial barrier to the first ππ*/πσ* conical intersection (CI) was found to be marginal, whereas the effects of a reduced torsional barrier of SH on the excited ππ* state and the mitigated slope of the πσ* PES between the first (ππ*/πσ*) and the second (πσ*/S 0 ) CIs were noticeable. The effect of the slope on the branching ratio has never been previously noticed. It was shown that the branching ratio can be sufficiently above unity without pre‐excitation of the torsion mode of SH, which has been assumed so far.