Organonitrogen groups in metal carbonyl complexes. Part IX. Amidino-derivatives of some π-cyclopentadienyl compounds

Abstract

Lithioamidines, R′NC(R)NR′Li, react with [(π-C₅H₅)M(CO)₃Cl](M = Mo or W) to form the complexes [(π-C₅H₅)-M(CO)₂{R′NC(R)NR′}](R = Ph; R′= H, Ph, or p-tolyl) in which the organonitrogen group acts as a bidentate 3-electron-donor ligand. Bidentate attachment of the amidino-ligand is considered to be of the σ,σ-type, unlike the isoelectronic allyl group. No corresponding amidino-complexes of carbonyl(π-cyclopentadienyl)iron could be isolated at room temperature and the complex [(π-C₅H₅)Ni{PhNC(Ph)NPh}], obtained from [(π-C₅H₅)Ni-(PPh₃)Cl], appears to be polymeric, possibly through NCN bridges.