β-双亚胺稀土双烷基配合物催化邻甲氧基苯乙烯高间规聚合研究  

Highly Syndiotactic Polymerizationof ortho-Methoxystyrene with β-Diketiminato Rare-earth Metal Complexes

作　　者：王田田 孙碧玮 吴春姬[1] 崔冬梅[1,2] Tian-tian Wang;Bi-wei Sun;Chun-ji Wu;Dong-mei Cui(State Key Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied Chemistry,Chinese Acadamy of Sciences,Changchun 130022;School of Applied Chemistry and Engineering,University of Science and Technology of China,Hefei 230026)

机构地区：[1]中国科学院长春应用化学研究所、高分子物理与化学国家重点实验室,长春130022 [2]中国科学技术大学应用化学与工程学院,合肥230026

出　　处：《高分子学报》2024年第6期729-737,共9页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号52273016,22331010)资助项目

摘　　要：设计合成了一类氮原子上含脂肪族取代基的β-双亚胺的配体及其相应的稀土金属配合物1~3.在助催化剂有机硼盐和烷基铝的作用下,将配合物1~3用于催化邻甲氧基苯乙烯(oMOS)聚合中,制得了高间规选择性(rrrr>99%)聚合物,所得聚合物的玻璃化转变温度Tg为-90℃,熔点Tm为240℃.将配合物2用于催化异戊二烯(IP)均聚合,得到了以1,4-结构为主(含量约88.6%)的聚合物,玻璃化转变温度Tg为-57℃.此外,借助DFT理论计算,发现配位模式是决定邻甲氧基苯乙烯聚合物立体选择性的关键.The coordination polymerization of polar monomers encounters the significantly challenging and long standing problem in the academic research field,similar to other olefins bearing polar functional groups.However,the key to polymerization is the design of the catalyst.β-Diketiminate ligands have gained increasing popularity since the mid 1990s due to their suitability as spectator ligands.Additionally,β-diketiminate ligands have become some of the most widely used bidentate N-donor ligands in coordination chemistry nowadays.Interest inβ-diketiminate complexes was focused mostly on their application in olefin,notably ethylene,polymerization or on investigations of the ligand coordination mode,which varies between in-planeκ2-coordination and out-of-planeη4/5-coordination.In this work,a series of rare earth metal complexes 1-3 bearingβ-diketiminiato ligands featuring aliphatic substituents were designed and synthesized readily.In the presence of cocatalysts[Ph3C][B(C6F5)4]and AliBu3,complexes 2 and 3 were highly active for polymerization of ortho-methoxystyrene(oMOS)to afford syndiotactic polymers(rrrr>99%).These methoxyl functionalized polystyrenes have melting temperatures around 240℃and a Tg of-90℃.Complex 2 showed high 1,4 selectivity(88.6%)for isoprene polymerization.Finally,we demenstrate that the stereoselectivity was determined by the coordination patterns of monomer using density functional theory(DFT)calculations clearly.

关 键 词：稀土催化剂 高间规选择性 邻甲氧基聚苯乙烯 

分 类 号：TQ316.3[化学工程—高聚物工业]