摘要
用简单的“模板”合成法合成了氯化-(1,4,8,11-四氮杂环十四-1,3,8,10-四烯)合镍(Ⅰ)(Ni(tactdte)Cl2 )和氯化-(1 ,4.8.11,15-五氮杂环十八-1 ,3,8,10-四烯)合镍(Ⅱ)(Ni-(Pacodte)Cl2 )两种新络合物.用 NaOCl水溶液作氧化剂,水溶性镍(Ⅰ) 络合物为催化剂,在无有机溶剂和相转移剂存在的条件下,环氧化苯乙稀制得苯基环氧乙烷,其中Ni(tactdte)C12.Ni(pacodte)Cl2 ,Ni(phen)Cl2,Ni(bpy)2 Cl2 和 Ni(bpy)Cl2 具有较高的催化环氧化能力,以Ni(bpy)2 Cl2 为最佳,其转化率和选择性分别为100% 和81% ;反应过程中形成的精细黑色固体为此催化体系的活性物种.最后考察了催化剂的回收和重复使用情况.
A simple 'template' synthetic method has been applied to the synthesis of two aqueous soluble nickel ( Ⅱ ) complexes, Ni (tactdte)Cl2 (A) , Ni (pacodte) Cl2 (B) (tactdte = 1,4,8,11-tetraazacyclotetradeca-l, 3,8,10-tetraene, pacodte = 1,4,8,11,15-pentaazacyclooctadeca-1,3,8, 10-tetraene). Catalytic epoxidation of styrene by several aqueous soluble nickel ( Ⅱ ) complexes with NaOCl in the absence of organic solvent and phase transfer agent has been studied. (A), (B) and some other nickel ( Ⅱ ) complexes of bidentate heterocyclic amines such as Ni(bpy)Cl2, Ni(bpy)2Cl2(C) and Ni(phen)2Cl2(D) have been found to be active for epoxidation of styrene, and (C) is the best one (100% conversion and 81% selectivity). Finally, the reusing of catalyst (C) has been studied and some meaningful results have been given.
基金
中国科学院"八五"重点科研资助项目.
关键词
苯乙烯
镍配合物
次氯酸钠
催化
环氧化
styrene, nickel complex, sodium hypochlorite, catalytic epoxidation
