REDUCTIVE ELECTROPOLYMERIZATION OF COMPLEXES CONTAINING AN ALDEHYDE-SUBSTITUTED DERIVATIVE OF 2,2'-BIPYRIDINE

Polypyridyl complexes of Fe(II) and Zn(II) containing the ligand 4-methyl-2,2'-bipyridyl-4'-carboxalde-hyde(4-CH3-4'-CHO-bpy) have been prepared. Upon electrochemical reduction of these complexes coupling reactions occur at the ligands, yielding thin metal-complex-containing polymeric films on the electrode surfaces. The polypyridyl ligands that form in a polymerized film of [Zn(4-CH3-4'-CHO-bpy)3]2+ have been isolated following chemical degradation and characterized using fast atom bombardment mass spectrometry and H-1 nuclear magnetic resonance. These and other results are consistent with a mechanism for polymerization that involves radical-radical coupling at the aldehyde substituents following reduction. The coupling occurs with the formation of a 1,2-diol linkage between the bipyridine ligands which creates a basis for network polymerization.