SYNTHESIS, CHARACTERIZATION AND REDOX BEHAVIOR OF ISOMERIC[OSA2L2] [A=NO2-,SCN- OR N3- AND L=2-(ARYLAZO)PYRIDINE]COMPLEXES

Both blue-violet (2) and red-violet (3) isomers of [OsX2L2] where X = Cl or Br; and L (1) = 2-(arylazo)pyridine react smoothly with A (A = N O2-, SCN- or N3-) in boiling aqueous ethanol affording species of the type [OsA2L2] (4 and 5, respectively). From spectral data the stereore tentivity of the reaction is proposed. The new complexes are electroac tive and display one metal-centred oxidation and successive ligand-bas ed reductions in MeCN solutions. Chemical reactivity of these species is also studied.