ELECTROCHEMICAL N-DOPING OF POLY(DITHIENYLVINYLENE) - A COMPARISON OFCYCLOVOLTAMMETRIC AND CONDUCTIVE PROPERTIES IN N-DOPING AND P-DOPING

Electrochemical n-doping of poly(dithienylvinylene) has been performed in AN + 0.1 M N(CnH2n+1)4+ClO4-(n = 1,2,3,4 and 6) and compared with p-doping. Cyclic voltammetry, in situ ESR and UV-Vis spectroelectroche mistry show that radical anions produced in n-doping are moderately un stable towards disproportionation whereas, in p-doping, radical cation s are stabilized by pi-dimerization. In situ conductivity of n-doped p olymer decreases as the size of the dopant cation increases, suggestin g charge transport control by interchain hopping. The different conduc tivities of n- and p-doped polymers are due to the different sizes of the counterions.