OXIDATION OF STYRENE CATALYZED BY MU-OXOTRINUCLEAR MIXED-VALENCE AND MIXED METAL CARBOXYLATE COMPLEXES

Catalytic oxidation of styrene and cumene was carried out in the absence of solvent with μ-oxotrinuclear mixed valence and mixed metal carboxylate complexes as catalysts. Main products from styrene are styrene oxide and benzaldehyde. Among these complexes tested, the μ-oxo mixed metal acetate complexes FeIII2ZnII, CoIII2CoII, and CrIII2FeII are superior for both reactivity and epoxide selectivity to monomeric or trinuclear homometal complexes. Moderately high temperatures (80-95°C) and decreased 02 pressure result in increased epoxide selectivity. Cumene was oxidized by all the complexes tested, but the FeIII2MnII complex had no activity for the oxidation of styrene. Electron transfer between metals via a μ-oxo atom is considered to be responsible for the effective catalytic feature. © 1992.