Exploring the reactivity of tungsten bis(imido) dimethyl complexes with methyl aluminium reagents: implications for ethylene dimerizationCCDC reference numbers 769100-769102. For crystallographic data in CIF or other electronic format see DOI: 10.1039/c0dt00110d

• Main Authors: Wright, William R. H, Batsanov, Andrei S, Howard, Judith A. K, Tooze, Robert P, Hanton, Martin J, Dyer, Philip W
• Format: Article
• Language: English
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c0dt00110d

The reaction of [WCl 2 (NAr) 2 (DME)] ( 1 ) with excess Me 3 Al affords the dimethyl complex [WMe 2 (N{Ar}AlMe 2 {μ-Cl})(NAr)] ( 2 ), which on treatment with THF or MeAlCl 2 yields [WMe 2 (NAr) 2 (THF)] ( 3 ) and [WMe 2 (N{Ar}AlMe(Cl){μ-Cl})(NAr)] ( 5 ), respectively. Complex 3 is unstable in solution dissociating to form [WMe 2 (NAr) 2 ] ( 4 ) that may be isolated as an adduct with PMe 3 , [WMe 2 (NAr) 2 (PMe 3 )] ( 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 C 2 H 4 /C 2 D 4 (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. Reaction of [WCl 2 (NAr) 2 (DME)] with AlMe 3 affords the bimetallic dimethyl complex [WMe 2 (N{Ar}AlMe 2 {μ-Cl})(NAr)], which is inert towards ethene. Displacement of the Lewis acid moiety by THF affords a complex that initiates C 2 H 4 dimerization.