Photochemical activation of pincer-ligated phosphoranides: mechanistic insight for reduction of aryl halides

Abstract

Pincer-ligated phosphoranides constitute a relatively underexplored subclass of main-group compounds whose distinctive structural and electronic properties are now attracting renewed interest. In this study, we report the synthesis, full characterization, and novel photoreactivity of O,N,O-pincer ligated phosphoranide anions. Upon visible-light irradiation, these species engage in single-electron transfer (SET) processes with various aryl halides, enabling the formation of C–P and C–C bonds. A combination of electrochemical studies and TD-DFT calculations supports a mechanism involving the formation of electron donor–acceptor (EDA) complexes, followed by light-induced SET and radical recombination. These findings introduce these phosphoranides as a versatile platform for photochemical transformations and underscore the broader potential of main-group frameworks in light-driven redox chemistry.