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Visible‐Light‐Triggered Molecular Photoswitch Based on Reversible E / Z Isomerization of a 1,2‐Dicyanoethene Derivative
Author(s) -
Guo Xin,
Zhou Jiawang,
Siegler Maxime A.,
Bragg Arthur E.,
Katz Howard E.
Publication year - 2015
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.201410945
Subject(s) - photoswitch , isomerization , photochemistry , photochromism , molar absorptivity , chemistry , thermal stability , irradiation , visible spectrum , materials science , organic chemistry , optics , catalysis , physics , optoelectronics , nuclear physics
A designed bis(dithienyl) dicyanoethene‐based, strictly E / Z photoswitch (4TCE) operates through state‐selective ( E and Z isomer) photoactivation with visible light. The E and Z isomers of 4TCE exhibit remarkably different spectroscopic characteristics, including a large separation (70 nm) in their absorption maxima ( λ max ) and a 2.5‐fold increase in molar extinction coefficient from cis to trans . The energetically stable trans form can be completely converted to the cis form within minutes when exposed to white light, whereas the reverse isomerization occurs readily upon irradiation by blue light ( λ <480 nm) or completely by thermal conversion at elevated temperatures. These features together with excellent thermal stability and photostability of both isomers make this new E / Z photoswitch a promising building block for photoswitchable materials that operate without the need for UV light.