Thiophenylazobenzene: An Alternative Photoisomerization Controlled by Lone-Pair⋅⋅⋅π Interaction.

ABSTRACT: 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 orthogon

SUBMITTER: Slavov C 

PROVIDER: S-EPMC6973119 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature