Ethylene polymerisation and oligomerisation with arene-substituted phenoxy-imine complexes of titanium: investigation of multi-mechanism catalytic behaviour
作者:James A. Suttil、David S. McGuinness、Michael G. Gardiner、Stephen J. Evans
DOI:10.1039/c3dt32183e
日期:——
A range of unsubstituted (1,2) and 6-substituted (3–5) ortho-phenoxy-imine ligands have been prepared and converted to their silyl ether derivatives (6–10). Reaction of silyl ethers with TiCl4(thf)2 in the case of the unsubstituted species yields bis-ligated complexes while the substituted species react cleanly to yield complexes of the form [Ti(O^NR)Cl3(thf)]. In most cases the complexes have been characterised by X-ray crystallography. Testing of the complexes for ethylene oligomerisation and polymerisation has been undertaken employing alkylaluminium co-catalysts (AlEt3, MAO). In all cases the predominant product formed is polyethylene however careful analysis of the liquid phase reveals a complex process by which 1-butene is most likely formed via Cossee mechanism while 1-hexene results from a metallacyclic process.
我们制备了一系列未取代(1,2)和 6-取代(3-5)的正交苯氧基亚胺配体,并将其转化为硅基醚衍生物(6-10)。未取代的硅基醚与 TiCl4(thf)2 反应生成双配位络合物,而取代的硅基醚与 TiCl4(thf)2 反应生成[Ti(O^NR)Cl3(thf)]形式的络合物。在大多数情况下,络合物都通过 X 射线晶体学进行了表征。利用烷基铝助催化剂(AlEt3、MAO)对这些络合物进行了乙烯低聚和聚合测试。在所有情况下,形成的主要产物都是聚乙烯,但对液相的仔细分析显示了一个复杂的过程,其中 1-丁烯很可能是通过 Cossee 机制形成的,而 1-己烯则是通过金属环化过程形成的。