Photochemical Processes of Superbase Generation in Xanthone Carboxylic Salts.
Fiche publication
Date publication
décembre 2022
Journal
Angewandte Chemie (International ed. in English)
Auteurs
Membres identifiés du Cancéropôle Est :
Pr ALLONAS Xavier
Tous les auteurs :
Ley C, Siedel A, Bertaux T, Croutxé-Barghorn C, Allonas X
Lien Pubmed
Résumé
Photobase generators are species that allow the photocatalysis of various reactions, such as thiol-Michael, thiol-isocyanate, and ring-opening polymerization reactions. However, existing compounds have complex syntheses and low quantum yields. To overcome these problems, photobase generators based on the photodecarboxylation reaction were developed. We synthesized and studied the photochemistry and photophysics of two xanthone photobase, their carboxylic acid precursors, and their photoproducts to understand the photobase generation mechanism. We determined accurate quantum yields of triplet states and photobase generation. We demonstrated the effect of the intermediate radical preceding the base release. We characterized the photophysics of the photobase by femtosecond spectroscopy and showed that the photodecarboxylation process occurred from the second excited triplet state with a rate constant of 2.2 × 109 s-1.
Mots clés
photobase generator, photochemistry, photophysics, photodecarboxylation, caged compounds
Référence
Angew Chem Int Ed Engl. 2022 12 19;: