稀土席夫碱配合物催化己内酯可控开环聚合(英文)  

Controlled Ring-Opening Polymerization of ε-Caprolactone Catalyzed by a Rare Earth Schiff-Base Complex

作　　者：倪旭峰[1] 朱伟伟[1] 沈之荃[1] 

机构地区：[1]浙江大学高分子科学与工程学系,教育部高分子合成与功能构造重点实验室,浙江杭州310027

出　　处：《催化学报》2010年第8期965-971,共7页

基　　金：Supported by the National Natural Science Foundation of China (20774078);the Special Funds for National Basic Research Program of China (973 Program,G2005CB623802);the Scientific Research Foundation for Returned Scholars,Ministry of Education of China

摘　　要：通过稀土氯化物与席夫碱钠盐的交换反应制备了一系列以3,5-二叔丁基水杨醛缩苯胺为配体的稀土席夫碱配合物.对其中的钕席夫碱配合物进行了X射线单晶衍射分析,发现其单晶结构为五角双锥构型,所得席夫碱稀土配合物可以单组分催化ε-己内酯开环聚合.深入研究了钕席夫碱配合物催化己内酯的开环聚合机理,考察了不同聚合条件对单体转化率、产物分子量及分子量分布的影响.结果表明,该聚合反应速率为一级,聚合反应具有较好的可控性.聚合物端基分析表明,聚合反应以配位-插入机理进行.Lanthanide Schiff-base complexes with the formula [3,5-tBu2-2-（O）C6H2CH=NC6H5]3Ln（THF） （Ln=Sc,Y,La,Nd,and Gd） were synthesized by the metathesis reaction of anhydrous LnCl3 with a Schiff-base sodium salt in good yields （ 〉80%）.The complex containing a neodymium center was characterized by X-ray diffraction and the structure around the neodymium atom could be described as a pentagonal bipyramid.The ring-opening polymerization （ROP） of ε-caprolactone （CL） was successfully carried out using the lanthanide Schiff-base complexes as catalysts,and the neodymium complex leads to a controlled ROP of CL.The influence of the reaction conditions on the monomer conversion,molecular weight,and molecular weight distribution of the resultant polymers was investigated.The polymerization rate was first-order with respect to the monomer concentration.End-group analyses of the oligomer of CL showed that the polymerization underwent a coordination-insertion mechanism.

关 键 词：己内酯 开环聚合 稀土催化剂 席夫碱 晶体结构 

分 类 号：O643.32[理学—物理化学]