Ruthenium cationic species for transfer hydrogenation of aldehydes: Synthesis and catalytic properties of [(PPh3)2Ru(CH3CN)3Cl]+[A]− {A = BPh4 or ClO4} and structure of [(PPh3)2Ru(CH3CN)3Cl]+[BPh4]−

The compounds, [(PPh3)2Ru(CH3CN)3Cl] [BPh4] (1) and [(PPh3)2Ru(CH3CN)3Cl] [ClO4] (2) have been synthesized from reactions of [Ru(PPh3)3Cl2] with Na[BPh4] and NaClO4 · H2O, respectively, in acetonitrile. The compound 1 has been structurally characterized. The geometry of this complex is that of a distorted octahedral, with cationic Ru(II) center bonded two triphenylphosphine ligands in the axial position and three acetonitrile and one chloride ligands present in the basal positions. The ruthenium compounds are catalytically active for the conversion of aldehydes and ketones to alcohols at 90 °C using 2-propanol as the source of hydrogen in the presence of K2CO3.