Chiral Salan Aluminium Ethyl Complexes and Their Application in Lactide Polymerization
作者:Hongzhi Du、Aldrik H. Velders、Pieter J. Dijkstra、Jingru Sun、Zhiyuan Zhong、Xuesi Chen、Jan Feijen
DOI:10.1002/chem.200900799
日期:2009.9.28
state, adopting a cis‐(O,O) and cis‐(Me,Me) ligand geometry. From the results of variable‐temperature (VT) 1H NMR in the temperature range of 220–335 K, 1H–1H NOESY at 220 K, and diffusion‐ordered spectroscopy (DOSY), it is concluded that each diastereoisomer b is also monomeric with a five‐coordinated aluminium central core. The geometry is intermediate between square pyramidal with a cis‐(O,O), trans‐(Me
手性四齿苯氧胺(salan-型)配体支持的铝乙基络合物的合成途径[Al(OC 6 H 2(R-6-R-4)CH 2)2 CH 3 N(C 6 H 10)NCH 3 } -C 2 ħ 5 ](4,7:R = H; 5,8:R =氯; 6,9:R = CH 3)的报告。在环己烷环上具有(R,R)构型的对映体纯的salan配体1-3提供了配合物4,5,和6 2个非对映异构(作为混合物一和b)。通过X射线分析确定,每个非对映异构体a为固态的五配位铝中心核,呈顺式(O,O)和顺式(Me,Me)配体几何结构。根据220-335 K温度范围内的变温(VT)1 H NMR ,220 K下1 H- 1 H NOESY的结果以及扩散有序光谱法(DOSY)得出的结论是,每个非对映异构体b也是具有五配位铝中心核的单体。几何形状是正方形锥体之间中间体与顺式- (O,O),反式- (ME,ME)配位体配置和三角双锥与反式-