Substituted o-quinodimethane complexes of ruthenium(0)

Abstract

Reactions of [RuCl₂L₄](L = PMe₃ or PMePh₂) with the lithium salts of 1,2,3-trimethyl-, 1,2,3,4-tetramethyl-, or 1,2,4,5-tetramethyl-benzene lead to complexes which contain co-ordinated methyl substituted o-xylidene moieties. Spectroscopic studies confirm the metal-ligand interaction as intermediate between (σ²,π) and (π²) and the o-xylidene moieties can be better described as methyl substituted o-quinodimethanes. By contrast reaction of the lithium salt of o-xylene with [RuCl₂{P(OPh)₃}₄] gives the o-metallated compound [[graphic omitted]OPh)₂){P(OPh)₃}₃] whilst reaction of the lithium salt of 3,4-dimethylanisole with [RuCl₂(PMe₃)₄] gives [[graphic omitted]H₂Me₂)(PMe₃)₄] with binding through a phenyl carbon atom. The structures of these complexes have been assigned by spectroscopic means.