芳香醛亚胺与一氧化碳的交替共聚反应

Alternating Copolymerization of Aryl Aldehyde Imines and Carbon Monoxide

以苯乙酰基四羰基钴作为催化剂,研究了对芳香醛亚胺与一氧化碳(CO)的交替共聚反应.采用6种芳香醛亚胺单体,分别与CO进行交替共聚反应,得到了6种新的多肽类聚合物.利用核磁共振谱、红外光谱、凝胶渗透色谱(GPC)及MALDI-TOF质谱等对聚合物的结构进行了表征.探讨了芳香醛亚胺苯环上取代基的位阻效应和电子效应对聚合反应的影响.结果表明,聚合物链终止端存在3种不同类型的端基,分别具有慕尼黑酮类结构、咪唑啉类结构以及酰胺类结构,对这些端基的形成机理进行了讨论.

Alternating copolymerization of aryl aldehyde imines and CO,using phenylacetyl tetracarbonyl cobalt as catalyst,was investigated in details. The reactions were carried in dioxane at 50 ℃ under 6 MPa of CO pressure,and six new polypeptide products were obtained from copolymerization of the corresponding aryl imines and CO. The steric and electronic effects of substituents at the phenyl rings were examined,which showed obvious influences on the molecular weight of the polymerization products as well as the copolymerization. The structures of the polypeptide products were characterized by naclear magnetic resonance（ NMR）,Infrared（ IR）,gel permeation chromatography（ GPC） as well as matrix-assisted laser desorption / ionization time of flight mass spectrometry（ MALDI-TOF MS） methods. According to the MS results,there existed three kinds of new end group structures at the terminal ends of the polymerization products,which should correspond to münchnone,imidazoline and amide structures,respectively. Possible mechanisms for the formation of the three kinds of end groups were discussed.