单金属锰、铁卟啉对空气氧化α-蒎烯的催化作用及取代基效应  

Catalysis and Substituent Effects of Monomanganese-porphyrins and Monoiron-porphyrins for α-Pinene Oxidation with Air

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,长沙410082

出　　处：《高等学校化学学报》2005年第9期1695-1698,共4页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:20376018;20436010);国家"八六三"计划(批准号:2002AA321070)资助.

摘　　要：以α-蒎烯为底物,空气作氧化剂,研究了苯环上带有不同取代基团的单锰卟啉和单铁卟啉对空气氧化α-蒎烯的催化作用及反应中的取代基效应.结果表明,单锰卟啉及单铁卟啉催化氧化α-蒎烯得到双键和烯丙位一、二级碳氢键的氧化产物,没有烯丙位三级碳氢键的氧化产物.环氧化合物是主要产物,而且氧化产物的产率随时间的变化呈较好的线性关系.随着苯环上meso位取代基Cl,CH3,OCH3和OH的供电子能力的增强,锰卟啉和铁卟啉对α-蒎烯的催化活性逐渐减弱,α-蒎烯的转化率逐渐降低.锰卟啉和铁卟啉的催化反应表观速率常数k与环外苯基上的取代基特性常数σ均呈良好的线性关系,Hammett关系式分别为lnk=1·2168σ-7·9968,lnk=0·6251σ-8·2426;线性相关系数分别为0·9507和0·9715.Catalysis and substituent effects of monomanganese-porphyrins and monoiron-porphyrins with different substituents on the phenyl rings for α-pinene oxidation with air were studied. The results showed that the product mixture was composed of components resulting from the oxidation of C = C bond and allylic secondary and primary C—H bonds in α-pinene. No oxidation products of allylic tertiary C—H bond were detected, the main component of the product mixture was α-pinene oxide. The yields of various oxidation products increased linearly with the increase of the reaction time when α-pinene oxidation was catalyzed by the experimental mentallo-porphyrins. With increasing the electron-donating abilities of the substituents on the meso sites of phenyl rings of monomanganese-porphyrins and monoiron-porphyrins, their catalytic activities was weakened and the conversions of α-pinene decreased. There were linear relationships between the reaction kinetic constant k and the substituent constant σ of the two kinds of metallo-porphyrins, and the Hammett equations： Ink = 1. 2168σ - 7. 9968 for monomanganese-porphyrins and Ink = 0.6251 σ - 8. 2426 for monoiron-porphyrins. The linear coetticients were 0.950 7 and 0.971 5, respectively.

关 键 词：Α-蒎烯 金属卟啉 催化 氧化 取代基效应 

分 类 号：O643.3[理学—物理化学]