Synthesis, characterization and reactivity of polypyridyl ruthenium(II) carbonyl complexes with phosphine derivatives: Ruthenium–carbon bond labilization based on steric and electronic effects

Ruthenium phosphine complexes with a CO ligand [Ru(tpy)(PR3)(CO)Cl]+ (tpy = 2,2′:6′,2″-terpyridine, R = Ph or p-tolyl), were prepared by introduction of CO gas to the corresponding dichloro complexes at room temperature. New carbonyl complexes were characterized by various methods including structural analyses. They were shown to release CO following the addition of several N-donors to form the corresponding substituted complexes. The kinetic data and structural results observed in this study indicated that the CO release reactions proceeded in an interchange mechanism. The molecular structures of [Ru(tpy)(PPh3)(CO)Cl]PF6, [Ru(tpy)(P(p-tolyl)3)(CO)Cl]PF6 and [Ru(tpy)(PPh3)(CH3CN)Cl]PF6 were determined by X-ray crystallography.