these complexes were characterized by NMR spectra, X-ray crystallography, and elemental analysis. We elucidated the step-reaction mechanism between the yttrium dialkyl complex based on bulky phosphazene ligand and trialkylaluminum, which might shed new light on the formation process of active species in organoaluminum-dependent Ziegler–Natta catalytic systems.
钇二烷基前体[N [Ph 2
PNC 6 H 3(i Pr)2 ] 2 Y(CH 2 SiMe 3)2 ](1)与超过3当量的
三甲基铝或
三乙基铝反应,得到双核杂
金属配合物N [Ph 2
PNC 6 H 3(i Pr)2 ] 2 Y (μ-R)2 AlR 2 } R(R = Me(2),Et(3))。当
三甲基铝载量降低到2当量,在相同的反应,得到产物N- [PH 2
PNC 6 ħ 3(我PR)2 ] 2 Ý(μ-Me)的2(μ-CH 2森达3)阿尔梅}我(4),具有完全不同的粘合模式。所有这些配合物均通过NMR光谱,X射线晶体学和元素分析进行了表征。我们阐明了基于庞大的
磷腈
配体的二烷基
钇二烷基络合物与三烷基铝之间的阶跃反应机理,这可能为依赖
有机铝的齐格勒-纳塔催化体系中活性物种的形成过程提供了新的思路。