Stereospecific formation of polypyridylruthenium(II) complexes incorporating an asymmetrical bidentate ligand: Influence of coligands

The reaction of an asymmetrical bidentate 2-phenylazopyridine (pap) ligand with a ruthenium carbonyl dimer ([Ru(bpy)(CO)Cl2]2; bpy = 2,2′-bipyridine) results in cleavage of the chloro bridge and the formation of cationic [Ru(bpy)(pap)ClX]+ complexes. In addition to spectroscopic characterization, the structures of the [Ru(bpy)(pap)Cl(CO)]PF6 and [Ru(bpy)(pap)Cl(CH3CN)]PF6 complexes were determined by single crystal X-ray diffraction studies. The structurally characterized complexes had different configurations with regard to the pap ligand. The coligands (CO and CH3CN) play an important role in the incorporation of the asymmetrical bidentate ligand.