Synthesis of Ti(iv) complexes of donor-functionalised phenoxy-imine tridentates and their evaluation in ethylene oligomerisation and polymerisation
School of Chemistry, University of Tasmania, Private Bag 75, Hobart 7001, Australia; Sasol Technology Ltd, PO Box 1183, Sasolburg 1947, South Africa
A number of analogues of the Mitsui Chemicals ethylene trimerisation system (IV) have been explored, in which one of the donor atoms have been modified. Thus, a series of mono-anionic tridentate phenoxy-imine (3-(t-butyl)-2-(OH)- C6H4CN(C(CH3)2CH2OMe) 1, 3-(adamantyl)-2-(OH)-C6H4CN(2′-(2′′- (SMe)C6H4)-C6H4) 2, 3-(t-butyl)-2-(OSiMe3)-C6H4CN(C(CH 3)2CH2OMe) 3) or phenoxy-amine (3,5-di(t-butyl)-2-(OH)-C6H4CH2-N(2′- (2′′-(OMe)C6H4)-C6H4) 4) ligands have been prepared and reacted with TiCl4 or TiCl 4(thf)2 to give the mono-ligand complexes 5-7. The solid state structures of compounds 4-6 have been determined. Complexes 5-7 have been tested for their potential as ethylene oligomerisation/polymerisation systems in conjunction with MAO activator and benchmarked against the Mitsui phenoxy-imine trimerisation system IV. While the phenoxy-amine complex 6 shows a propensity for polymer formation, the phenoxy-imine complexes 5 and 7 show somewhat increased formation of short chain LAOs. Complex 5 is selective for 1-butene in the oligomeric fraction, while 7 displays liquid phase selectivity to 1-hexene. As such 7, which is a sulfur substituted analogue of the Mitsui system IV, displays similar characteristics to the parent catalyst. However, its utility is limited by the lower activity and predominant formation of polyethylene. © 2013 The Royal Society of Chemistry.
1-Hexene; Donor atoms; Liquid Phase; Mitsui Chemicals; Phenoxy-imine; Polymer formation; Solid-state structures; Ti complexes; Butenes; Complexation; Ethylene; Nitrogen compounds; Oligomerization; Oligomers; Phenoxy resins; ethylene; ethylene derivative; imine; organometallic compound; phenol derivative; phenoxyl radical; titanium; article; chemical structure; chemistry; polymerization; synthesis; Ethylenes; Imines; Models, Molecular; Molecular Structure; Organometallic Compounds; Phenols; Polymerization; Titanium