检索规则说明:AND代表“并且”;OR代表“或者”;NOT代表“不包含”;(注意必须大写,运算符两边需空一格)
检 索 范 例 :范例一: (K=图书馆学 OR K=情报学) AND A=范并思 范例二:J=计算机应用与软件 AND (U=C++ OR U=Basic) NOT M=Visual
作 者:阳卫军[1] 张磊[1] 李永进[1] 郭灿城[1]
机构地区:[1]湖南大学化学与化工学院,湖南长沙410082
出 处:《分子催化》2012年第4期314-321,共8页Journal of Molecular Catalysis(China)
基 金:国家自然科学基金(批准号:20606008);中央高校基本科研业务费(批准号:53110704012)资助
摘 要:以苯乙烯、环己烯和反式二苯乙烯为烯烃底物,以双氧水、叔丁基过氧化氢和异丙苯过氧化氢为氧化剂,以苯环上对位和邻位氯取代的四苯基金属卟啉为仿生催化剂,对烯烃的催化环氧化反应进行了对比研究.讨论了不同氯取代位的四苯基金属卟啉对烯烃环氧化性能的影响.实验结果表明,在没有助催化剂存在下,邻位氯代的四(2,6-二氯苯基)铁(锰)卟啉对烯烃的环氧化具有优异的催化性能,烯烃底物的转化率和环氧选择性都比对位氯代的四苯基铁(锰)卟啉高,且反应条件温和.其中FeⅢ(TDCPP)Cl的催化性能最好,环氧化选择性最高,催化氧化苯乙烯时,环氧苯乙烷的选择性达到了90.4%.相同金属离子不同配体的金属卟啉传递氧原子的能力为TDCPP>T(p-Cl)PP>TPP.氧化剂的结构对环氧化物的选择性有较大影响.过氧键连有吸电子基团的异丙苯过氧化氢对环氧化物的选择性最高.根据实验结果,对金属卟啉催化环氧化机理进行了分析.The reaction of hydrogen peroxide, tert-butyl hydrogen peroxide or cumene hydrogen peroxide with styrene, cyclohexene and trans-stilbene, catalyzed by phenyl ortho or para CI substituent position of tetraphenylmetalloporphyrins, have been studied in this paper. Effect of different C1 substituent position on the catalytic per- formance for olefins epoxidation of tetraphenylmetalloporphyrins has been investigated. The results show that 5,10, 15,20-tetrakis- ( 2,6-dichlorophenyl ) porphyrin iron ( or manganese) chloride ( Fem ( TDCPP ) C1 or Mn Ⅲ ( TDCPP ) C1) on the epoxidation of olefin exhibits excellent catalytic properties, which the olefins conversion and epoxide selectivity is better than the tetra- (p-chorophenyl) -porphyrin iron ( or manganese) chloride ( Fe ^Ⅲ T (p-C1) PPC1 or Mn^Ⅲ T(p-C1)PPC1), and the reaction conditions is mild. FeZ(TDCPP) C1 exhibits the best catalytic performance and epoxide selectivity. When it applied to catalyze oxidation of styrene, the styrene oxide selectivity reached 90.4%. The catalytic performance of different metalloporphyrin ligands with same metal ions are in the following order: TDCPP〉T(p-Cl)PP〉TPP. Oxidant structure affects the selectivity of epoxides. Cumene hydrogen perox- ide, which peroxy bond links with electron drawing groups, gets the highest epoxide selectivity. According to the experimental results, the metalloporphyrins' epoxidation mechanism is also analyzed.
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在链接到云南高校图书馆文献保障联盟下载...
云南高校图书馆联盟文献共享服务平台 版权所有©
您的IP:216.73.216.117