Selective Oxidation of 2,6-di-tert-butylphenol by Oxygen Adducted Pentadentate Schiff Base Cobalt () Activated Catalysts and Electrochemical Properties of Cobalt () Catalysts in Aprotic Solvents

摘要

Activated oxidation catalysts are generated by the treatment of pentadentate Schiff base cobalt(￥±) complexes with the oxygen saturated DMF solution. Oxidation of 2,6-di-tert-butylphenol by homogeneous oxidation catalysts of superoxo type pentadentate schiff base cobalt(￥2) complexes yields 2,6-di-tert-butylbenzoquinone(BQ) as a major product. And O2/Co mole ratio of homogeneous oxidative catalysts such as [Co(￥2)(sal-DET)]O2 and [Co(￥2)(sal-DPT)]O2 by PVT method of the oxygen absorption in DMSO and pyridine solution was 1:1, 1:1.52 in DMF solution and ￥ì-peroxo type cobalt(￥2) complexes formed at solid state. The redox reaction processes of superoxo type cobalt(￥2) complexes as homogeneous oxidation catalysts were investigated by cyclic voltammetry and DPP method at a glassy carbon electrode. As a result of electrochemical measurements the reduction processes of oxygen adducted superoxo type cobalt(￥2) complexes occurred to four steps including prewave of O2-in 0.1M TEAP-DMSO and 0.1 M TEAP-Pyridine as supporting electrolyte solution.