Tandem catalysis using group 5 and 6 imido complexes and group 4 permethylindenyl catalysts

R2Si(C5R'4)(R' N)MX2形式的约束几何催化剂（CGC）配合物对聚乙烯的合成有很大的兴趣；无论是工业上还是科学上。此外，近年来，O'Hare团队已经合成了一些基于4基二氯乙烯基（I*）配合物的新型茂金属，用作乙烯聚合催化剂。乙烯低聚化，从乙烯中产生更高的α -烯烃，是工业研究的前沿。这包括二巯醇、甲丁醇和菲利普斯三聚化工艺。奥黑尔集团的研究表明，钨亚胺配合物在溶液和浆液相中对乙烯二聚化成1-丁烯具有极强的活性和选择性。最近发现Nb(CHSiMe3)(NAr)(OC(CF3)3)(PMe3)2（图2(b)）形式的铌亚胺配合物对降冰片烯的开环复分解聚合有活性。串联催化涉及两种或两种以上催化剂的协同作用，以获得单个催化剂单独无法获得的产物。在文献中已经报道了许多串联催化系统，无论是在溶液中，还是最近在非均相中。Karbach和他的同事们开发了一种硅支撑的系统，可以将1-己烯掺入到聚合物链中。乙烯聚合催化剂——这部分项目的目的是合成通式R12SB(R2N,I*)MX2的新型4族受限几何I*配合物，并将其开发成商业上可行的乙烯聚合催化剂。乙烯齐聚催化剂-本项目的目的包括合成形式为M(NAr)Cl3的铌和钽亚胺配合物。THF， M(NAr)Me2Cl和固载当量。然后，这些配合物将被开发成商业上可行的高α -烯烃低聚催化剂，特别是具有高选择性的1-辛烯或1-丁烯。串联催化-最终目的是在固体载体（如聚甲基铝氧烷）上同时支持乙烯聚合和寡聚化催化剂，以便从单一乙烯进料源形成LLDPE。该项目属于EPSRC物理科学研究领域。该项目特别关注催化，旨在开发乙烯聚合和低聚的新催化剂。

Complexes known as constrained geometry catalysts (CGC) of the form R2Si(C5R'4)(R''N)MX2 are of great interest for the synthesis of polyethylene; both industrially and scientifically. Furthermore, in recent years, the O'Hare group have synthesised a number of novel metallocenes based on group 4 permethylindenyl (I*) complexes for use as ethylene polymerisation catalysts.Ethylene oligomerisation, generating higher alpha-olefins from ethylene, is as the forefront of industrial research. This includes the Dimersol, Alphabutol and Phillips trimerisation processes. Work within the O'Hare group has shown that tungsten imido complexes to be extremely active and selective towards the ethylene dimerisation to 1-butene in both the solution and slurry phase. Recently niobium imido complexes of the form Nb(CHSiMe3)(NAr)(OC(CF3)3)(PMe3)2 (Figure 2(b)) were found to be active towards the ring opening metathesis polymerisation of norbornene.Tandem catalysis involves the cooperative action of two or more catalysts to afford a product that is not accessible by the individual catalyst alone. There have been a number of reported tandem catalytic systems reported in the literature, both in solution, and more recently in the heterogeneous phase. Karbach and co-workers developed a silica-supported system that allowed incorporation of 1-hexene into at polymer chain.Ethylene polymerisation catalysts - the aim of this part of the project is to synthesise new group 4 constrained geometry I* complexes of the general formula R12SB(R2N,I*)MX2 with intention of developing them into commercial viable ethylene polymerisation catalysts. Ethylene oligomerisation catalysts - the aims of this project include the synthesis of niobium and tantalum imido complexes of the form M(NAr)Cl3.THF, M(NAr)Me2Cl and the solid supported equivalents. These complexes will then be developed into commercially viable ethylene oligomerisation catalysts for higher alpha-olefins, in particular 1-octene or 1-butene with high selectivity.Tandem catalysis - the final aim is to simultaneously support both an ethylene polymerisation and an oligomerisation catalyst on a solid support, such as polymethylaluminoxane, in order to form LLDPE from a single ethylene feed source.This project falls within the EPSRC Physical Sciences research area. In particular this project focuses on catalysis with the aim to develop new catalysts for ethylene polymerisation and oligomerisation.