Neutral and cationic aluminium complexes containing a chiral (OSSO)-type bis(phenolato) ligand: synthesis, structures and polymerization activity
作者:Bing Lian、Haiyan Ma、Thomas P. Spaniol、Jun Okuda
DOI:10.1039/b909287k
日期:——
two square pyramidal aluminium centers with two "fly-over" bis(phenolate) ligands. The neutral methyl aluminium complexes are active in the polymerization of methyl methacrylate (MMA) and in the ring-polymerization of rac-lactide (LA), producing PMMAs and PLAs in a controlled fashion. The cationic aluminium complexes were active in the cationic polymerization of isoprene and benzofuran.
三甲基铝与连接的双(苯酚)反式-1,4-二硫代环己烷二基-2,2-双(4,6-二叔丁基苯酚)(cydtbpH2,1a)的反应生成手性甲基铝络合物[Al(cydtbp [Me](2a)为外消旋体和拆分对映体,通过多核NMR光谱和元素分析对其进行表征。Rac- 反式-1,2-二硫代环己烷二基-2,2-双(6-叔丁基-4-甲基苯酚)}(cytbmpH2,rac-1b)类似地得到rac-2b。(S,S)-2a和rac-2b的单晶X射线衍射显示出严重扭曲的三角双锥面几何形状,且Al-S距离明显不同。rac-2b与(-)-冰片的反应得到烷氧基配合物5,为两种非对映异构体的混合物。使用B(C6F5)3从中性金属配合物rac-2a中提取甲基,得到阳离子配合物[rac-Al(cydtbp)(THF)2] + [MeB(C6F5)3]-(rac-6 x(THF)2 )根据X射线晶体学,采用八面体配位几何。使