【摘要】 研究了西佛碱钴络合物和四苯基卟啉钴（TPP-Co）在CHCl₃溶剂中对各种酚的催化氧化性能。发现TPP-Co在室温下可使萘酚氧化成萘醌。在催化氧化α-萘酚过程中,TPP-Co的钴主要处于二价状态,三价卟啉钴的浓度很小。提出了TPP-Co催化α-萘酚氧化为萘醌的可能反应机理。更多还原

【Abstract】 Effects of cobalt Schiff-base (Salen-Co) and cobalt tetraphenyl-porphyrin (TPP-Co) on the oxidation of different phenols with CHC13 as solvent have been investigated. It is found that TPP-Co can oxidize naphthol to forni naphthoquinone at room temperature. The order of the oxidation rate for different phenol species is as follows:by Salen-Co: a-naphthol>2, 6-di-t-butyl-p-cresol>2, 4-xylenol>2, 6-xylenol>B-naphthol>o-cresol>phenol=0;by TPP-Co: a-navphthol> 2, 6-di-t-butyl-p-cresol>B-naphthol>2, 6-xylenol, o-cresol, phenol=0.Effects of different central metals such as V4+O, Co2+, Cuz+, and substituted groups of periphery in metalloporphyrins on oxidation of a-naphthol have also been investigated. It is found that - only Co2+ porphyrin shows catalytic activity. Both V4+O and Cu2+ porphyrins can not be used as catalyst to oxidize naphthol. Catalytic activity of the para-substituting group of cobalt tetraphenylporphyrins is -OCH3> -H> -COOH.Some interesting results about the effect of reaction conditions, such as temperature, TPP-Co concentration and substrate concentration, on the oxidation of a-naphthol are obtained. Negative temperature coefficient of reaction rate is observed in the range of 0-20C.A reaction mechanism of a-naphthol oxidation by TPP-Co is proposed.更多还原