Catalytic Activity of Metal Polyphthalocyanines in Autoxidation Reactions

Abstract
The oxidation of cumene and acrolein was carried out using metal polyphthalocyanines as a catalyst. The catalyst activated an oxygen molecule to form a phthalocyanine–O2 complex, which then abstracted the hydrogen atom of a reactant to initiate the oxidation. The catalyst had no effects on the decomposition of cumene hydroperoxide, formed selectively in the oxidation of cumene. The addition of a small amount of pyridine induced a drastic shortening of the induction period as well as a considerable increase in the oxidation rate. The initiation mechanism assumed on the basis of findings on the desorption of oxygen from the catalyst and on the effect of pyridine was confirmed by a kinetic study of the homogeneous liquid-phase oxidation of acrolein.