polyethylene waxes of low molecular weight and narrow distribution (1.1 - 1.8), incorporating predominantly vinyl/methyl and some methyl/methyl end-groups, are a feature of the materials obtained. The influence of steric/electronic changes to the pre-catalyst and polymerization reaction parameters on both the catalytic activities as well as the properties of the polymeric product has been the subject
五种结构相关的
铬 (III) 配合物,[2-(ArNCMe)-8-(NAr)C9H8N]CrCl3 (Ar = 2,6-Me2Ph Cr1, 2,6-Et2Ph Cr2, 2,6-i-Pr2Ph Cr3, 2,4,6-Me3Ph Cr4, 2,6-Et2-4-MePh Cr5),每个都带有一个不对称的双(亚
氨基)三氢
喹啉配体,已经以良好的产率合成并完全表征。Cr2 的分子结构在
金属中心显示出扭曲的八面体几何形状,空间庞大的 N,N,N-
配体采用 mer-构型。在用 MAO 或
MMAO 活化时,Cr1 - Cr5 是
乙烯聚合的高活性催化剂,在 80°C 下最有效(高达 15.96 × 106 g (PE)*mol-1 (Cr)*h-1);即使在 100°C,活性仍保持良好
水平(2.92 × 106 g (PE)*mol-1 (Cr)*h-1)。低分子量和窄分布 (1.1 - 1.8) 的高