James J. Tazuma

Selective autoxidation of some phenols using salcomines and metal phthalocyanines

Abstract The autoxidation of 2,6-dialkyl substituted phenols has been studied using salcomines, the complexes derived from cobalt (II) and schiff bases of salicylaldehyde and ethylenediamine, and metal phthalocyanines (M-Pc) in N, N′ -dimethylformamide. With salcomines and Co(II)-Pc, the predominant products are the corresponding 2,6-dialkylbenzoquinones along with some minor quantities of 3,3′,5,5′-diphenoquinones. This is the first reported use of a phthalocyanine complex in selective oxidation of disubstituted phenols. Solvent and temperature affect the course of oxidation and the selectivity to products. With phthalocyanine complexes of Cu(II), Mn(II), or Fe(II), diphenoquinone compounds originating from the coupling of aroloxy radicals are favored over benzoquinones. Mechanistic aspects are proposed to explain the course of oxidation. Salcomines also catalyze the oxidation of monoalkylphenols and phenol but require higher temperature and more severe conditions. Co(II)-Pc, the most active of the phthalocyanine complexes tested, also catalyzes the oxidation of monoalkylphenols to a limited degree but does not affect phenol itself.

Hydrogenation over heterogeneous alkali metal catalyst

Product distributions from the reaction of mixtures of hydrogen, deuterium, and ethylene at 150/sup 0/C on 30% potassium on ..gamma..-alumina were consistent with an ionic mechanism involving reversible dissociative hydrogen chemisorption, reversible dissociative ethylene adsorption, and nonreversible hydrogenation of adsorbed ethylene species to ethane.