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Updated: May 7, 2026

Determination of the Photoisomerization Quantum Yield of a Hydrazone Photoswitch
Published on: February 7, 2022
Robust visible light photoswitching with ortho-thiol substituted azobenzenes
Subhas Samanta1, Theresa M McCormick, Simone K Schmidt
1Department of Chemistry, University of Toronto, 80 St. George St. Toronto, ON M5S 3H6, Canada. awoolley@chem.utoronto.ca.
Abstract:
Introduction of S-ethyl groups in all four ortho positions of azobenzene prevents reduction of the azo group by intracellular glutathione, while enhancing the absorptivity to ~10,000 M(-1) cm(-1) in the blue and green regions of the visible spectrum. cis-to-trans isomerization occurs thermally on the minutes timescale. Further, this substitution pattern permits switching with red light, a color that is more penetrating through biological tissues than other parts of the visible spectrum.
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