MECHANISM OF OXIDATIVE DEHYDROGENATION OF AN AMINE COORDINATED TO OSMIUM(II)

The synthesis and characterization of [Os(bpy)2(ampy)]2+ {bpy = 2,2'-b ipyridine; ampy = 2-(aminomethyl)pyridine} have been studied, together with its irreversible two-electron oxidative dehydrogenation to the c orresponding osmium(ii) imine species in aqueous solution, by utilizin g electrochemical and stopped-flow kinetic techniques. The kinetic dat a were analysed by using numerical integration methods to obtain solut ions for the differential equations derived from mechanistic proposals . The results were consistent with the initial oxidation of the metal centre to Os(III) and the intermediacy of a deprotonated Os(IV) specie s, formed by disproportionation, in the subsequent ligand dehydrogenat ion.