MMA with longer-chain alkyl methacrylates. In sharp contrast, the 1/2B(C6F5)3 combination exhibits low to negligible polymerization activity due to the formation of ineffective adduct Cp2Zr[OC(OiPr)CMe2]+[OC(OiPr)CMe2B(C6F5)3]− (2). Such a profound Al vs. B Lewis acid effect has also been observed for the lithium ester enolate; while the Me2CC(OiPr)OLi/2Al(C6F5)3 system is highly active for MMA polymerization
路易斯酸E(C 6 F 5)3(E = Al,B)对茂
金属和
锂酯烯醇盐介导的官能化烯烃如
甲基丙烯酸甲酯(
MMA)和N,N-二甲基
丙烯酰胺(
DMAA)聚合的剧烈影响, Cp 2 Zr [OC(O i Pr)CMe 2 ] 2(1)和Me 2 CC(O i Pr)OLi均已记录和阐明。在
金属茂双的情况下(烯醇甲酯)1,当与2当量组合。Al(C 6 F 5)3的,可实现
MMA和
DMAA的高活性离子对聚合;这种聚合体系的活性使得可以合成
MMA与长链甲基
丙烯酸烷基酯的明确定义的二嵌段和三嵌段共聚物。与之形成鲜明对比的是,由于形成了无效的加合物Cp 2 Zr [OC(O i Pr)CMe 2 ] + [OC(O i Pr)),因此1 / 2B(C 6 F 5)3组合的聚合活性低至可忽略不计。CMe 2 B(C 6 F 5)3 ] −(2)。对于烯醇
锂酯,也观察到了如此强烈的Al vs. B Lewis酸效应。而我2