In the presence of metallotetraphenylporphyrins [(Co(II)TPP, Fe(III)TPPCl, Mn(III)TPPCl, Cu(II)TPP, and Zn(II)TPP, TPP = tetraphenylporphyrin], the oxidation of RC6H4CHO (R = H, 4-Cl) with mol. oxygen has been investigated. The oxygen uptake and changes in the electronic spectrum of metallotetraphenylporphyrins during the course of the reaction were measured. It was observed that besides Co(II)TPP that can reversibly bind mol. oxygen, Fe(III)TPPCl and Mn(III)TPPCl which are not capable of binding mol. oxygen reversibly can also catalyze the oxidation of aldehydes, while Cu(II)TPP and Zn(II)TPP are inactive. The oxidation reaction, however, is catalyzed by some catalytically active species which is formed from the interaction between metalloporphyrin and percarboxylic acid accumulated during the course of the reaction with the destruction of porphyrin ring, and is inhibited by the metalloporphyrin itself. In the reaction systems, the metalloporphyrins are nominal catalysts. It seems that the catalytic role of metallotetraphenylporphyrin in the oxidation of aromatic aldehydes should not be attributed to its capability of activating mol. oxygen.

Key words: PORPHINE P, OXIDATION, CATALYST, ZINC COMPLEX, IRON COMPLEX, COPPER COMPLEX, COBALT COMPLEX, ALDEHYDES, AROMATIC COMPOUNDS, MANGANESE COMPLEX