金属卟啉的电化学性质与其催化氧化α-蒎烯性能的关系  

Relationship between Electrochemical Behavior of Metalloporphyrins and Their Catalytic Performance for α-Pinene Oxidation

作　　者：阳卫军[1] 郭灿城[1] 毛彦利[1] 李国成[1] 

机构地区：[1]湖南大学化学化工学院,湖南长沙410082

出　　处：《催化学报》2005年第5期360-364,共5页

基　　金：国家自然科学基金 (2 0 3 760 18;2 0 43 60 10 );国家高技术研究发展计划 (863计划 ) (2 0 0 2AA3 2 10 70 )资助项目

摘　　要：采用循环伏安法对一系列四苯基金属卟啉的电化学氧化还原性质进行了研究,考察了四苯基金属卟啉的第一还原电位与其催化氧化α蒎烯性能的关系.结果表明,各四苯基金属卟啉催化空气氧化α蒎烯转化率的大小顺序为TPPMnⅢCl >TPPCoⅢCl>TPPFeⅢCl>TPPCuⅡ≈TPPNiⅡ≈TPPZnⅡ,除TPPCoⅢCl外,基本与其第一还原电位的大小顺序一致.随着卟啉环上取代基供电子能力的减弱,各取代基铁卟啉和锰卟啉的第一还原电位E1值均逐渐减小,表现在催化体系中是它们越容易被还原而引发反应,催化氧化α蒎烯的转化率逐渐升高.The electrochemical property of some metalloporphyrins and its relationship to the catalytic oxidation of α-pinene were investigated by cyclic voltammetry method. The results showed that the conversion of α-pinene oxidation catalyzed by the metalloporphyrins with air decreased in the order TPPMn~ⅢCl>TPPCo~ⅢCl>TPPFe~ⅢCl>TPPCu~Ⅱ≈TPPNi~Ⅱ≈TPPZn~Ⅱ,which was in accordance with the order of their first reduction potentials except TPPCo~ⅢCl. With the decrease of the electron-releasing capability of different substituents in the porphyrin rings, the first reduction potentials of the substitutional iron tetraphenylporphyrins and manganese tetraphenylporphyrins reduced, and the conversion of α-pinene oxidation catalyzed by the metalloporphyrins increased, which indicated that the metalloporphyrins were easily reduced to initiate the catalytic reaction. A good linear relationship was obtained between the first reduction potentials and the characteristic constants ( σ ~*) of meso -position substituents on the porphyrin ring of the iron tetraphenylporphyrins and manganese tetraphenylporphyrins.

关 键 词：金属卟啉 锰 铁 第一还原电位 催化氧化 Α-蒎烯 取代基常数 

分 类 号：O643.3[理学—物理化学]