Ligand-to-metal charge transfer facilitates photocatalytic oxygen atom transfer (OAT) with -dioxo molybdenum(vi)-Schiff base complexes.

Systems incorporating the -Mo(O) motif catalyse a range of important thermal homogeneous and heterogeneous oxygen atom transfer (OAT) reactions spanning biological oxidations to platform chemical synthesis. Analogous light-driven processes could offer a more sustainable approach. The -Mo(O) complexes reported here photocatalyse OAT under visible light irradiation, and operate a non-emissive excited state with substantial ligand-to-metal charge-transfer (LMCT) character, in which a Mo[double bond, length as m-dash]O π*-orbital is populated transfer of electron density from a chromophoric salicylidene-aminophenol (SAP) ligand.