Catalytic properties of some adducts of the coordination compounds of transitional metals with molecular oxygen

The paper studies the oxidation of 2,6-di-t-butylphenol (DtBuF), with O-2, in the presence of some catalysts based on Co(II) complexes with Schiff bas es, in DMF solution and hi the presence of pyridine. The transformation deg ree, the reaction time and reactivity of the oxidation products depend on t he nature of the substituents grafted on the ligand molecule. The non-react ed DtBuF and oxidation products separated by the catalyst through column ch romatography, have been analysed by H-1-NMR spectroscopy and gas chromatogr aphy. The formation, in high yields of 2,6-di-t-butylbenzoquinone (QN), as the main products of the oxidation reaction, and of 2,6,2',6'-tetra-t-butyl diphenoquinone (DFQ) in traces, puts into evidence the reversible formation of [L.Co .O-2] adducts and also of the peroxidic radicals.