A novel donor-acceptor polymer based on thiophene and isopyrazole has been prepared for use in n-doping applications. Nonpolymerizable monomer radical cations appear to be the predominant oxidation product, resulting in a need for extended cycling to produce adequate quantities of polymer for characterization. The electrochemical behavior of the polymer films produced is strongly dependent upon the conditions applied during electrodeposition and on the solvent used during cycling of the films. Cycling to reductive potentials during oxidative polymerization in acetonitrile was necessary to produce a polymer film capable of n-doping, likely resulting from a need to establish pathways for cation migration. The neutral polymer undergoes oxidation to the p-doped form at ca. 2000 mV vs Ag/Ag+ in propylene carbonate and reduces back to neutral at ca. 0 mV. Conversion of the neutral polymer to its n-doped form involves reductions at -700 and -1300 mV, with reoxidation at -800 and -200 mV to return to the neutral form of the polymer. (c) 2007 The Electrochemical Society.