摘要
本文研究了水溶性金属卟啉存在下丁硫醇的氧化过程,考察了金属卟啉的中心金属离子、周围基团及轴向配体与其催化活性之间的关系.发现只有钴卟啉对硫醇的氧化反应有明显的催化作用.卟啉环的周围基团对钴卟啉的催化性能有显著影响,其活性顺序为:CoTPyP>Co(p-SO_3Na)TPP>Co(p-oH)TPP>Co(p-NH_2)TPP>CoTPP.研究了各种动力学因素(底物浓度、催化剂浓度、碱浓度和吡啶添加物浓度)与硫醇转化速度之间的关系并借助设想的催化循环解释了反应的动力学规律.
In the presence of water-soluble metalloporphyrins, the autoxidation of n-butyl mercaptan has been studied. When different metallotetrapyridyl-porphyrins (CoTPyP, MnTPyPCl, FeTPyPCl, NiTPyP, CuTPyP, ZnTPyP) were used as catalysts, only CoTPyP exhibited distinct activity. With different cobalt porphyrins as catalysts, the activity decreased in the order of CoTPyP>Co(p-SO_3Na)TPP>Co(p-OH)TPP> Co(p-NH_2) TPP>CoTPP.
The relationship between the reaction rate and the thiol concentration was measured. At high concentrations a saturation effect was observed. Michealis-Menten kinetics appear to be obeyed. The effect of some kinetic factors (the concentration of catalyst, the concentration of alkali, and the concentration of pyridine additive) on the oxidation reaction has also been investigated. A RS-CoPor-O_2 intermediate seems to be required for the catalytic oxidation of thiols.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
1991年第5期477-482,共6页
Acta Chimica Sinica
基金
国家自然科学基金资助的项目
