New experiments involving electrochemistry, Auger spectroscopy and elemental analysis of films and film-forming compounds, as well as X-ray crystallography and electrochemistry of a key model compound, have been used to elucidate the linkage structure and probable mechanism of formation of oxidatively generated polymeric and copolymeric films of phenanthroline-containing complexes of ruthenium. Film formation evidently involves indirect electrochemical activation of coordinated 1,10-phenanthroline to nucleophilic attack by the non-coordinated pyridyl nitrogen of a dipyridyl ligand singly coordinated to a second metal center. The resulting linkage is comprised of a carbon/nitrogen bond with an excess positive charge residing on the nitrogen atom. Electrochemical oxidation of a complexed metal ion (typically Ru(II)) drives the polymerization by : (a) rendering the 4 site of phenanthroline significantly electrophilic, and (b) providing an oxidizing equivalent for eventual H atom elimination and pyridinium ion formation via an internal electron transfer sequence.