摘要
研究了从三氯化钕甲基磷酸二仲辛酯配合物(NdCl_3·3p_(350))与烷基铝(AlR_3)反应体系中分离出的Nd-A]双金属活性体的组成及其定向聚合活性。由Ndcl_3·3P_(350)-Al[(CH_2)_7-CH_3]_3及Al(C_2H_5)_3体系所得活性体的激光拉曼光谱发现,该活性体中存在稀土—碳键,可能的组成为Nd-(CH_2)_7CH_3及Nd-CH_2CH_3。这是稀土催化体系中存在稀土烷基化反应的直接证据。据此提出了一个可能的活性中心形成过程。实验结果表明,无需AlR_3存在,单独使用上述活性体即可引发双烯烃聚合,并具有较高的活性和高的定向性。
Composition and stereospecific polymerization activity of Nd-Al bimetallic complex isolated from the reaction system of NdCl3.3P350 with AlR3 has been studied. Laser Raman spectrum data and other experimental results show that there is Nd-C bond in the complex, wich can be considered as a direct evidence for the alkylation of rare earth with AlR3 in the system. The complex alone can initiate the diene polymerization with definite activity and high stere-oregularity. For various AlR3, the activity for butadiene polymerization is in the following order:Al(C2H5)3>HAl(i-Bu)2>Al(i-Bu)3籄l[(CH2)7CH3)3. Based on the results, a presumable formation process of the active species was proposed.
基金
国家自然科学基金
