J. Iran. Chem. Soc., Vol. 7, No. 1 March 2010, pp.128~133.

Current location: JICS Archive > Vol. 7 > No. 1 > Articles : 13

Oxidation of 2,6-Di-tert-butylphenol by Dioxygen Catalyzed by Tetrasodium Phthalocyaninatocobalt(II) Tetrasulfonate in Aqueous Micellar Media

M. Hassanein*, M. Sakaran and S. Shendy

Chemistry Department, Faculty of Science, Tanta University, Tanta 3152, Egypt

     The oxidation of 2,6-di-tert-butylphenol by dioxygen has been investigated in aqueous micellar aggregates of cetyltrimethylammonium bromide (CTAB) using tetrasodium phthalocyaninatocobalt(II) tetrasulfonate (CoPcTsNa4) as catalyst. The CTAB/CoPcTsNa4 system showed enhanced catalytic activity in the oxidation of 2,6-di-tert-butylphenol compared to that observed in the oxidation reaction in the absence of CTAB. 2,6-Di-tert-butyl-1,4-benzoquinone and 3,5,3',5'-tetra-tert-butyl-4,4-diphenoquinone were identified as reaction products. The initial rate constants of auto-oxidation reaction was found to increase with increasing the pH range from 7.0 to 13.0. The rate constants kobs of auto-oxidation reaction showed linear dependence on catalyst concentration. The rate of auto-oxidation reaction was found to fit a Michealis-Menten kinetic model for the saturation of catalyst sites with increasing 2,6-di-tert-butylphenol concentration and dioxygen pressure. Tetrasodium phthalocyaninatocobalt(II) tetrasulfonate in aqueous micellar solution of CTAB was found to be mainly monomeric.   

Keywords: Oxidation, Dioxygen, Cobaltphthalocyanine, 2,6-Di-tert-butyl-phenol, Surfactant, Catalysis

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