A dinuclear Co(II) complex with pyrrole substituents has been found to undergo reductive polymerization but does not polymerize under oxidizing conditions. The polymerization occurs on a variety of substrate electrode materials. It involves cleavage of the pyrrole rings from the complex and therefore represents a new method for the generation of electropolymerized metallopolymer films. The resulting polymer is porous and can be reversibly reduced at a formal potential of ca. - 1.5 V/SSCE. It becomes electronically conductive when reduced and is electrochromic. The potential dependence of its electronic spectrum and the observation that reduction at -1.8 V involves the gain of only 0.5 electrons per dinuclear Co unit suggest that its electrochemistry involves delocalized orbitals.