Catalytic Air Oxidation of Thiols Mediated at a Mo(VI)O2 Complex Center Intercalated in a Zn(II)-Al(III) Layered Double Hydroxide Host

While bis(2-mercapto-2,2-diphenyl-ethanoate) dioxomolybdate (VI), {MoO2[OOCC(S)(C6H5)2]2}2− (I), ethanolic solutions stoichiometrically react with aromatic and aliphatic thiols to give the corresponding disulfides, the intercalation of I within a Zn(II)-Al(III) layered double hydroxide (LDH) allows their catalytic oxidation by dioxygen. A reaction scheme is proposed in which a (MoIVO species activates O2, regenerating the parent (MoVIO2 complex (I), which then acts as a true catalyst. Kinetic data far the thiol oxidation reaction have been determined. The results obtained here demonstrate that the intercalation of I into a Zn(II)-Al(III) LDH host inhibits the formation of catalytically inactive (MoVO species that are always formed under homogeneous conditions.