以铑(Rh)金属有机配合物为催化剂,对手性-非手性N-炔丙基酰胺单体实施共聚反应,并利用圆二色(CD)和紫外-可见吸收(UV—Vis)光谱技术及旋光仪对共聚物的二级结构及光学活性进行了表征。结果表明聚合物产率高(≥96%),主链具有高立构规整性(顺式结构摩尔分数高于96%);相对于均聚物,共聚物的溶解性得到明显改善;非手性单体的庞大侧基有利于共聚物形成稳定的螺旋结构;少量的手性单体即可导致共聚物具有高光学活性;通过选择合适的手性共聚单体,非手性聚合物可被诱导形成单一手性螺旋结构,制备具有高光学活性的螺旋聚合物。
Copolymerizations of a ehiral and an achiral N-propargylamide monomer were carried out. The copolymers could be obtained in high yield using an Rh catalyst. The secondary structures and optical activities of the resulting copolymers were examined by UV-Vis and CD spectroscopies. The copolymers are found to have high cis content (≥96 % ) and improved solubility compared with the homopolymer. The bulky pendant groups of the aehiral co-monomer facilitate the adoption of stable helices by the copolymers. A small amount of chiral comonomer can lead to high optical activity of the copolymers. The copolymers followed well the“Sergeant and Soldiers” rule in the formation of the helical structures.