Synthesis and characterization of carbon-bridged bis(phenolate) lanthanum alkoxides and their catalytic behavior for the polymerization of L-lactide  

作　　者：LI BaoXia QI RuiPeng YAO YingMing ZHANG Yong SHEN Qi 

机构地区：[1]Key Laboratory of Organic Synthesis of Jiangsu Province,College of Chemistry,Chemical Engineering&Materials Science,Soochow University,Suzhou 215123,China

出　　处：《Chinese Science Bulletin》2012年第34期4442-4447,共6页

基　　金：supported by the National Natural Science Foundation of China (20972108, 21174095 and 21132002);the Priority Academic Program Developement of Jiangsu Higher Education Institutions, and the Qing Lan Project

摘　　要：Four lanthanum alkoxides stabilized by a carbon-bridged bis(phenolate) ligand were synthesized and their catalytic behavior for the ring-opening polymerization of L-lactide was explored. Reactions of [(MBMP)LaCp(THF) 2 ] (MBMP 2 = 2,2′-methylene-bis(6-tert-butyl-4-methyl phenoxo)) with HOCH 2 Ph, HOCH 2 CF 3 , HOCH(CH 3 ) 2 , and HOCH 2 CH 2 N(CH 3 ) 2 , respectively, in a 1:1 molar ratio in THF gave the dimeric lanthanum alkoxo complexes [(MBMP)Ln(μ-OR)(THF) 2 ] 2 (OR = OCH 2 Ph(1), OCH 2 CF 3 (2), OCH(CH 3 ) 2 (3), OCH 2 CH 2 N(CH 3 ) 2 (4)]. These complexes were well characterized, and the definitive molecular structure of complex 1 was determined. It was found that complexes 1 to 4 are efficient initiators for the ring-opening polymerization of L-lactide. The structure of the alkoxo groups has a significant effect on the catalytic behavior, and complex 2 can initiate L-lactide polymerization in a controlled manner.Four lanthanum alkoxides stabilized by a carbon-bridged bis（phenolate） ligand were synthesized and their catalytic behavior for the ring-opening polymerization of L-lactide was explored. Reactions of [（MBMP）LaCp（THF）2] （MBMP2- = 2,2＇-methylene- bis（6-tert-butyl-4-methyl phenoxo）） with HOCH2Ph, HOCH2CF3, HOCH（CH3）〉 and HOCH2CH2N（CH3）2, respectively, in a 1 ： 1 molar ratio in THF gave the dimeric lanthanum alkoxo complexes [（MBMP）Ln（gt-OR）（THF）2]2 （OR = OCH2Ph （1）, OCHzCF3 （2）, OCH（CH3）2 （3）, OCH2CHzN（CH3）2 （4）]. These complexes were well characterized, and the definitive molecular structure of complex 1 was determined. It was found that complexes 1 to 4 are efficient initiators for the ring-opening polymerization of L-lactide. The structure of the alkoxo groups has a significant effect on the catalytic behavior, and complex 2 can initiate L-lactide polymerization in a controlled manner.

关 键 词：L-丙交酯 催化行为 聚合反应 合成 醇盐 桥连 定碳 表征 

分 类 号：O631.3[理学—高分子化学]