Electrochemistry of Os(2,2′-bpy)2ClPyCH2NHCOPh tethered to Au electrodes by S–Au and C–Au junctions

Abstract

Osmium pyridine-bipyridine redox centers have been tethered to Au electrodes by chemical modification through Au–S and Au–C bonds respectively. 4-mercapto benzoic acid and the reduction product of the aryl diazonium salt of 4-amino benzoic acid were reacted on Au surfaces, with further post-functionalization by chemical reaction of the osmium complex amino-pyridine derivative with the surface carboxylates. The resulting modified Au surfaces were characterized by polarization modulated infrared reflection absorption spectroscopy (PM-IRRAS), scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), resonant raman spectroscopy and cyclic voltammetry.