Premium
Photoisomerization of Arylazopyrazole Photoswitches: Stereospecific Excited‐State Relaxation
Author(s) -
Wang YaTing,
Liu XiangYang,
Cui Ganglong,
Fang WeiHai,
Thiel Walter
Publication year - 2016
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201607373
Subject(s) - photoisomerization , excited state , relaxation (psychology) , enantiomer , chemistry , chemical physics , molecular physics , stereospecificity , physics , atomic physics , photochemistry , isomerization , stereochemistry , social psychology , catalysis , psychology , biochemistry
Abstract Electronic structure calculations and nonadiabatic dynamics simulations (more than 2000 trajectories) are used to explore the Z – E photoisomerization mechanism and excited‐state decay dynamics of two arylazopyrazole photoswitches. Two chiral S 1 /S 0 conical intersections with associated enantiomeric S 1 relaxation paths that are barrierless and efficient (timescale of ca. 50 fs) were found. For the parent arylazopyrazole (Z8) both paths contribute evenly to the S 1 excited‐state decay, whereas for the dimethyl derivative (Z11) each of the two chiral cis minima decays almost exclusively through one specific enantiomeric S 1 relaxation path. To our knowledge, the Z11 arylazopyrazole is thus the first example for nearly stereospecific unidirectional excited‐state relaxation.