Synthesis, spectral and catalytic dehydrogenation studies of ruthenium complexes containing NO bidentate ligands.

The synthesis and characterization of ruthenium mononuclear complexes containing NO bidentate ligands are reported. The complexes cis-[Ru(II)(bpy)2L](PF6)n (1a-c), [Ru(III)Cl(L)2(H2O)] (2a-b) and [Ru(III)Cl2(L)2]Cl (2c) were prepared by the reaction of cis-[Ru(II)Cl2(bpy)2]·2H2O (bpy=2,2'-bipyridine) and/or RuCl3·nH2O with the Ligands: 2-aminophenol (2-aph), 8-hydroxyquinoline (8-hq) and 4-aminoantipyrine (4-apy). These complexes were characterized by elemental analysis, spectroscopic (IR, UV-Vis, (1)H NMR, ESR) and magnetic susceptibility measurements. The ligand field parameters, Δo (splitting parameter), B (Racah parameter of interelectronic repulsion), and β (nephelauxetic ratio) were calculated. The redox properties were also investigated electrochemically by cyclic voltammetry. The complexes cis-[Ru(II)(bpy)2(8-hq)](PF6)2 (1b) and [Ru(III)Cl(8-hq)2(H2O)] (2b) have been investigated in conjunction with N-methylmorpholine-N-oxide (NMO) as co-oxidant for the catalytic dehydrogenation of benzyl amine, p-methyl benzylamine and p-nitrobenzylamine to their respective nitriles.