In this paper we report the first use of Al(III) salalen complexes for the ring opening polymerisation of rac-lactide. Polylactides with narrow polydispersities (PDIs range from 1.04–1.65) and moderate degrees of stereoselectivity were formed. Eight salalen Al(III) complexes have been prepared and fully characterised by solution-state NMR spectroscopy and, where appropriate, single crystal X-ray diffraction. With ligand 3H2 either a monomeric or dimeric Al(III) species was formed, the dimeric species was favoured at low concentrations. The complexes were tested for the ring opening polymerisation of rac-lactide in toluene at 80 or 100 °C. Interestingly, various tacticities of polymer were formed, which were dependent upon the nature of the group bound to the amine nitrogen centre.
在本文中,我们首次报道了使用 Al(III) salalen 复合物进行 rac-lactide 开环聚合的情况。该聚合反应生成了具有较窄聚分散度(PDI 在 1.04-1.65 之间)和中等立体选择性的聚内酯。通过溶液态核磁共振光谱和适当的单晶 X 射线衍射,制备了八种柳氮铝(III)配合物,并对其进行了全面的表征。
配体 3H2 可形成单体或二聚体 Al(III) 物种,低浓度时更倾向于二聚体物种。复合物在 80 或 100 °C的
甲苯中进行了 rac-内酰胺开环聚合试验。有趣的是,根据与胺氮中心结合的基团性质的不同,形成了各种不同性质的聚合物。