Propagation chains in photocatalyzed radical nucleophilic substitutions of thiolates with perfluoroalkyl groups

Abstract

Quantum yields and radical chain lengths have been investigated in photocatalyzed radical nucleophilic perfluorobutyl group substitution reactions of 2-mercaptothiolate anion under three different photocatalytic systems operating in reductive and quenching manners. Important propagation chain lengths have been uncovered with photocatalysts under both scenarios, reductive and oxidative. The different overall quantum yields and chain lengths observed demonstrate the balance between the efficiency of the photoinitiation events, propagation and termination steps. Theoretical calculations provide a better understanding and throw light into whether a closed or an open catalytic cycle is operating in photoinitiated perfluoroalkyl group- thiolate coupling reaction.