【摘要】 用光谱法研究了异戊二烯顺-1,4聚合催化体系 Ln（napb）₃-Al（i_C4H₉） ₃-Al₂（C₂H₅） ₃Cl₃中稀土离子的价态.结果表明,在上述催化体系中,镨,钕,钆,铒部以三价形式存在,这说明上述稀土化合物催化活性的不同,不是因为价态有所差异.对不同条件下含 Nd（naph）₃的催化剂溶液的光谱及聚合活性研究结果表明,催化活性与 Nd⁺³ 的特征吸收强度有关,吸收强度愈强,活性愈高.提高铝/钕克分子比及延长催化剂陈化时间,都导致特征吸收强度及催化活性的增大.更多还原

【Abstract】 Spectrophotometric study of the valence of rare earth ions in catalyst systemLn（naph）₃-Al（i-C₄H₉） ₃-Al₂（C₂H₅） ₃Cl₃ has shown that ions of Pr,Nd,Gd,and Er inthe catalyst system are in a valence state of 3,and the difference in their catalyticactivity toward isoprene polymerization is not due to the difference in their valencestate.The catalytic activity of the system Nd （naph）₃-Al（i-C₄H₉） ₃-Al₂（C₂H₅） ₃Cl₃ isrelated to the absorption intensity at 582mμ.The stronger is the absorption,thehigher is the catalytic activity.With increasing Al/Ln molar ratio and ageing timeof the catalyst,the absorption intensity at 582 mμ and the catalytic activity are alsoincreased.更多还原