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Updated: Jun 27, 2025

Determination of the Photoisomerization Quantum Yield of a Hydrazone Photoswitch
Published on: February 7, 2022
Structure and isomerization behavior relationships of new push-pull azo-pyrrole photoswitches
D Gallardo-Rosas1, J M Guevara-Vela2, T Rocha-Rinza3
1Instituto de Ciencias Nucleares, UNAM, Circuito Exterior, Ciudad Universitaria, Coyoacán C.P. 04510, Ciudad de México, Mexico. carmen.ortega@nucleares.unam.mx.
Abstract:
A family of stilbenyl-azopyrroles compounds 2a-d and 3a-d was efficiently obtained via a Mizoroki-Heck C-C-type coupling reaction between 2-(4'-iodophenyl-azo)-N-methyl pyrrole (1a) and different vinyl precursors. The influence of the π-conjugated backbone and the effect of the pyrrole moiety were correlated with their optical properties. Studies via UV-Visible spectrophotometry revealed that the inclusion of EWG or EDG favors a red-shift of the main absorption band in these azo compounds compared with their non-substituted analogues. Furthermore, there is a clear influence between the half-life of the Z isomer formed by irradiation with white light and the push-pull behavior of the molecules. In several cases, the stilbenyl-azopyrroles led to the formation of J-type aggregates in binary MeOH : H2O solvents, which are of interest for water compatible applications.
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