TY  - JOUR
A1  - Slavov, Chavdar
A1  - Yang, Chong
A1  - Heindl, Andreas Hans
A1  - Wegner, Hermann A.
A1  - Dreuw, Andreas
A1  - Wachtveitl, Josef
T1  - Thiophenylazobenzene: an alternative photoisomerization controlled by lone‐pair⋅⋅⋅π interaction
T2  - Angewandte Chemie. International edition
N2  - Azoheteroarene photoswitches have attracted attention due to their unique properties. We present the stationary photochromism and ultrafast photoisomerization mechanism of thiophenylazobenzene (TphAB). It demonstrates impressive fatigue resistance and photoisomerization efficiency, and shows favorably separated (E)‐ and (Z)‐isomer absorption bands, allowing for highly selective photoconversion. The (Z)‐isomer of TphAB adopts an unusual orthogonal geometry where the thiophenyl group is perfectly perpendicular to the phenyl group. This geometry is stabilized by a rare lone‐pair⋅⋅⋅π interaction between the S atom and the phenyl group. The photoisomerization of TphAB occurs on the sub‐ps to ps timescale and is governed by this interaction. Therefore, the adoption and disruption of the orthogonal geometry requires significant movement along the inversion reaction coordinates (CNN and NNC angles). Our results establish TphAB as an excellent photoswitch with versatile properties that expand the application possibilities of AB derivatives.
KW  - isomerization mechanisms
KW  - photochromism
KW  - photoswitches
KW  - thiophenylazobenzene
KW  - time-resolved spectroscopy
Y1  - 2019
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/57399
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-573993
SN  - 1521-3773
SN  - 1433-7851
VL  - 59.2020
IS  - 1
SP  - 380
EP  - 387
ER  -