The synthesis of olefin polymerization precatalysts: [TiCl 4(C 4H 7OCH 2CO 2CH 3)] and [(C 4H 7OCH 2CO 2Et) 2 Mg(μ-Cl) 2TiCl 4] · 2CH 2Cl 2. Crystal structures and properties

Abstract

Direct reactions of TiCl 4 or of a 1:1 mixture of TiCl 4 and MgCl 2 with chiral tetrahydrofurfuryl C 4H 7OCH 2CO 2CH 3 and C 4H 7OCH 2CO 2Et esters, respectively, gave [TiCl 4(C 4H 7OCH 2CO 2CH 3)] ( 1) and [(C 4H 7OCH 2CO 2Et) 2Mg(μ-Cl) 2TiCl 4] · 2CH 2Cl 2 ( 2) which are good precatalysts for ethylene polymerization. The crystal structures of 1 and 2 have been solved by X-ray methods. In 1 the titanium atom is octahedrally coordinated by four chlorine atoms and two oxygen atoms of the chelate tetrahydrofurfuryl acetate ligand. In the heterobimetallic complex 2, formed by slightly distorted edge-sharing octahedra, the titanium and magnesium atoms are separated by Ti ⋯ Mg of 3.725(16) Å and linked through two bridging Cl atoms.