Conversion of uncharged methyl complexes of ruthenium(II) into a cationic acyl complex: a mechanistic study
Abstract
Spectroscopic studies of the reactions of methyl complexes [Ru(CO)2(Me)X(PMe2Ph)2][X = Cl, (1a); X = I, (1b)] with Me3CNC have revealed that the end-product, [Ru(CO)(CNCMe3)2(COMe)(PMe2Ph)2]+(2), is formed via two isomers of the complexes [Ru(CO)(CNCMe3)(COMe)X-(PMe2Ph)2][X = Cl, (3a) and (4a); X = I, (3b) and (4b)]. Formation of the kinetically favoured isomers (3a) and (3b), from (1a) and (1b) respectively, is very rapid, while the relative rates of the isomerization and the further reaction with Me3CNC to yield (2) vary with the solvent and the halide ion X–. Two alternative mechanisms for the isomerization, involving dissociation of the isonitrile or the halide ligand, are discussed.