Abstract
Adsorption states of N,N′-dialkyl-4,4′-bipyridinium ions (viologens) and their cation radicals on a highly oriented pyrolytic graphite (HOPG) electrode surface were investigated by cyclic voltammetry and in situ infrared reflection-absorption spectroscopy (IRAS). A pair of spike-like anodic and cathodic waves was observed in the potential region well positive of the first reduction wave for the solution species. The peak potentials were found to depend on their alkyl chain length, and were shifted in the positive direction with the increase in the number of carbon atoms in the alkyl chains. Each pair is ascribed to a one-electron faradaic process of adsorbed viologens. It was indicated from IRAS measurements that the adsorbed cation radicals oriented with their longer molecular axis parallel to the HOPG surface, while the bipyridine ring planes were perpendicular to the surface (side-on configuration).
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
