摘要
本文用紫外可见光谱、红外光谱及磷核磁共振的方法,研究了稀土络合催化剂Nd(P_(204))_3-Al(i-Bu)_3-H_2O活性中心的形成过程。研究表明,在络合催化剂活性中心的形成过程中,稀土金属元素钕的价态不发生改变。Al(i-Bu)_3与Nd(P_(204))_3在反应过程中发生了两者之间的烷基交换反应: >Nd-P_(204)+>Al-i-Bu→i-Bu-Nd<+>Al-P_(204) 少量水的加入形成了稀土三元活性中心:>Nd-O-Al< 对Nd(P_(204))_3-Al(i-Bu)_3-H_2O聚合环氧化物引发机理也用^(31)P-NMR方法进行了研究。
The formation of active species of rare earth coordination catalyst composed of neodymium 2-ethylhexyl phosphonatestriisobutyl aluminum - water has been investigated by means of IR. UV and 3 IP{H} -NMR. The results showed that the oxidate valence of Nd has not changed during the reaction of Nd(P204)3 with Al(i-Bu)3, only the exchange of P204 in Nd(P204)3 with alkyl group in alkylaluminum occured:When catalytic ammount of water was added, the reaction of forming a metal-oxygen-metal species would take place. Al-O-Nd might be responsible for the high activity of rare earth coordination catalyst.The initiation mecha nism of rare earth coordination catalyst for the polymerization of epoxides has also been studied by the method of 31P{H}-NMR.
基金
国家自然科学基金
中国石化总公司资助
关键词
络合催化剂
稀土
发生
中心
聚合
rare earth coordination catalyst, active species, ring polymerigation opening
