title: Exploring the reactivity of tungsten bis(imido) dimethyl complexes with methyl aluminium reagents: implications for ethylene dimerization.
abstract: The reaction of [WCl2(NAr)2(DME)] (1) with excess Me3Al affords the dimethyl complex [WMe2(N{Ar}AlMe2{mu-Cl})(NAr)] (2), which on treatment with THF or MeAlCl2 yields [WMe2(NAr)2(THF)] (3) and [WMe2(N{Ar}AlMe(Cl){mu-Cl})(NAr)] (5), respectively. Complex 3 is unstable in solution dissociating to form [WMe2(NAr)2] (4) that may be isolated as an adduct with PMe3, [WMe2(NAr)2(PMe3)] (6). While complex 2 is inert towards ethylene, complex 3 reacts rapidly to afford a mixture of methane and but-1-ene (1:4). Neither complex 2 nor 3 react with propylene. Reaction of 3 with a C2H4/C2D4 (1:1) affords a mixture of isotopomers that is consistent with complete isotopic scrambling. The structures of complexes 1, 2, and 3 have been determined by X-ray diffraction.
authors.affiliation: Centre for Sustainable Chemical Processes, Department of Chemistry, Durham University, South Road, Durham, UK DH1 3LE.
authors.forename: William R H
authors.initials: WR
authors.lastname: Wright
authors.forename: Andrei S
authors.initials: AS
authors.lastname: Batsanov
authors.forename: Judith A K
authors.initials: JA
authors.lastname: Howard
authors.forename: Robert P
authors.initials: RP
authors.lastname: Tooze
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Hanton
authors.forename: Philip W
authors.initials: PW
authors.lastname: Dyer