Synthesis and substitution reactions of dichlorobis-triphenylphosphine[2-(N-(2-pyridinium-2-yl)-(carbamoyl-N-)-pyridine]ruthenium(II)

Spectroscopic and crystallographic studies show that 2-(N-(2-pyridyl)carbam oyl)pyridine (HL) in both its neutral and deprotonated forms, coordinates r uthenium(II) via the amidato- and pyridine-nitrogen atoms thereby forming f ive-membered rings. In neutral [Ru(HL)(PPh3)(2)Cl-2], HL exists as a zwitte rion and the molecular structure is stabilised, in part, by an intramolecul ar Cl . .N interaction. Reaction of the title complex with bidentate chelat ing ligands leads to the replacement of two chlorides by the bidentate liga nds, resulting in the formation of the mixed-ligand complexes. There is dep rotonation of the zwitterionic HL in the mixed-ligand complexes. (C) 2001 E lsevier Science Ltd. All rights reserved.