A kinetic study of the photoinduced oxo-transfer using a Mo complex anchored to TiO2

Abstract

Kinetic study of the photo-assisted oxygen atom transfer reaction (OAT) using a dioxo-Mo complex anchored on TiO2, stimulated by light, was performed at ambient conditions using triphenylphosphine (PPh3) as a model molecule. The kinetic of the OAT reaction was studied with three catalytic systems: 4,4’-dicarboxylate-2,2’-bipyridine-dioxochloromolybdenum (MoO2L/TiO2), H2MoO4 (H2MoO4/TiO2) and molybdenum oxide (MoO3/ TiO2) anchored to TiO2. The MoO2L/TiO2 gives conversion higher than 90% and selectivity (to phosphine oxide) close to 100%. MoO3/TiO2 did not allow the oxo-transference, suggesting the importance of the bipyridine ligand as an electronic connector between MoO2L unit and TiO2. With the MoO2L/TiO2 system was observed that when the photonic flux increases, the quantum yield, and the OAT reaction rate increases.