8-Quinolinolato gallium complexes: iso-selective initiators for rac-lactide polymerization.
8-Quinolinolato gallium complexes: iso-selective initiators for rac-lactide polymerization.
复制标题
DOI：
10.1021/ic4016756
复制
发表时间：
2013-11-04
影响因子：
4.6
通讯作者：
Williams CK
中科院分区：
文献类型：
--
作者：
Bakewell C;White AJ;Long NJ;Williams CK
合成了一系列8-羟基喹啉镓配合物，并对其结构进行了表征。配合物已被证明是外消旋丙交酯开环聚合的活性引发剂。高程度的聚合控制被证明，作为例证的线性演变的分子量作为聚合的进展，窄的多分散性指数，和分子量对应于那些预测的基础上的引发剂浓度。一些引发剂显示外消旋-丙交酯的等选择性聚合，其中Pi = 0.70。监测了聚合速率，并将假一级速率常数与类似铝化合物的速率常数进行了比较。8-羟基喹啉镓引发剂显示出比铝化合物系列高约3倍的速率，同时保持相当高的异构选择性（Pi = 0.70）和聚合控制。合成了一系列含8-羟基喹啉配体的镓配合物，并与已报道的一系列铝配合物进行了比较。发现这些配合物在高温（347 K）下对外消旋丙交酯的开环聚合具有活性。与它们的铝类似物相比，8-羟基喹啉镓配合物显示出改进的速率，并且在某些情况下保持良好程度的异选择性。
The synthesis and characterization of a series of 8-quinolinolato gallium complexes is presented, and the complexes are analogous to a series of aluminum complexes previously reported. The complexes have been shown to be active initiators for the ring-opening polymerization of rac-lactide. High degrees of polymerization control are demonstrated, as exemplified by the linear evolution of molecular weight as the polymerization progresses, narrow polydispersity indices, and molecular weights corresponding to those predicted on the basis of initiator concentration. Some of the initiators show iso-selective polymerization of rac-lactide, with Pi = 0.70. The polymerization rates have been monitored, and the pseudo first-order rate constants are compared to those of analogous aluminum compounds. The 8-quinolinolato gallium initiators show rates approximately 3 times higher than those of the series of aluminum compounds, while maintaining equivalently high iso-selectivity (Pi = 0.70) and polymerization control. A series of gallium complexes, bearing 8-quinolinolato ligands, have been synthesized and are related to a series of aluminum complexes already reported. The complexes were found to be active in the ring-opening polymerization of rac-lactide at elevated temperatures (347 K). The 8-quinolinolato gallium complexes show improved rates, as compared to their aluminum analogues, and in some cases maintain a good degree of iso-selectivity.
登录
查看更多内容
影响因子：
2.8
作者：
Normand, Mickael;Kirillov, Evgeny;Carpentier, Jean-Francois
通讯作者：
Carpentier, Jean-Francois
影响因子：
4.3
作者：
Nomura, Nobuyoshi;Ishii, Ryohei;Kondo, Tadao
通讯作者：
Kondo, Tadao
DOI：
10.1073/pnas.0602765103
发表时间：
2006-10-17
影响因子：
11.1
作者：
Hormnirun, Pirnpa;Marshall, Edward L.;White, Andrew J. P.
通讯作者：
White, Andrew J. P.
影响因子：
15
作者：
Pietrangelo, Agostino;Knight, Spencer C.;Tolman, William B.
通讯作者：
Tolman, William B.
影响因子：
2.8
作者：
Normand, Mickael;Dorcet, Vincent;Carpentier, Jean-Francois
通讯作者：
Carpentier, Jean-Francois