Oxygen atom transfer photocatalyzed by molybdenum(VI) dioxodibromo-(4,4′-dicarboxylate-2,2′-bipyridine) anchored on TiO2

The molybdenum(VI) dioxodibromo-(4,4′-dicarboxylate-2,2′-bipyridine) complex was anchored on a TiO2 solid matrix, fully characterized by 13C and 15N solid-state NMR spectroscopy and evaluated as an oxygen atom transfer agent under visible light (λ > 420 nm) irradiation. It was compared with the complex molybdenum(VI) dioxodibromo-(4,4′-dicarbomethoxy-2,2′-bipyridine) under homogeneous conditions. Two positive effects were observed: (1) an important reactivity increase due to the photogenerated electronic flux onto the molybdenum coordination sphere and (2) a catalyst life span amplification due to the isolation of the metallic centers allowing the catalytic system to be turned on and off in the presence or absence of O2.