茂金属化合物Cp2ZrCl2与硅胶表面相互作用分子模拟

利用分子力学、分子动力学和基于密度泛函理论的量子力学从头计算方法对茂金属化合物Cp_2ZrCl_2与含有不同基团的硅胶表面之间的相互作用进行了研究,发现茂金属化合物Cp_2ZrCl_2在双羟基表面的物理吸附最强,在单羟基表面的吸附强度次之,在硅氧烷基表面的吸附最弱。Cp_2ZrCl_2在双羟基作用下,中心金属原子与茂环之间的距离增加,导致茂环脱落,这是茂金属化合物直接负载到硅胶表面后活性较低的主要原因。

Molecular simulation studies on the interaction of Cp2ZrCl2 with the surface of sillica

Molecular simulation techniques,like molecular mechanic,molecular dynamic,and density functional theory-based ab-ini- tio quantum methods,were used to study the interaction between Cp_2ZrCl_2 and silica with different functional groups on the surface.It has been found that Cp_2ZrCl_2 can be most strongly adsorbed by silica gel with paired-hydroxyls on the surface compared with the ad- sorption strength on silica gel with single-hydroxyl or only oxy-silicon groups on the surface.Just because Cp_2ZrCl_2 can he so surongly adsorbed by silica gel with paired-hydroxyl on the surface,which makes cyclopentadienyl ligands easily be removed from Zr atom,that the supported metalloeene catalyst was not as active as the homogeneous one.