SYNTHESIS AND ELECTROCHEMICAL POLYMERIZATION OF POLY[3-(1-NAPHTHYLTHIOPHENE)]

3-(1-naphthylthiophene) was synthesized by a coupling reaction of a l- naphthyl Grignard reagent with 3-bromothiophene, catalyzed by Ni(II) c atalyst. Cyclic voltammetry of a 17 mM 3-(1-naphthylthiophene), 0.1 M Et4NBF4/acetonitrile solution yields an oxidation wave at about 1.2 V which corresponds to the formation of the radical cation. Galvanostati c deposition of poly [3-(1-naphthylthiophene)] was carried out at a cu rrent density of 12.5 mA/cm(2) and the potential of the electrode reac hed a plateau value of about 1.1 V vs. Ag/Ag+ after 50 s. The cyclic v oltammogram of the resulting polymer in 1 M Et4NBF4/acetonitrile is ch aracterized by anodic and cathodic waves at 0.9 and 0.8 V, respectivel y. The doping level of the polythiophene derivative was found to be eq ual to about 0.2 which indicates that every five thiophene units carry one positive charge. Cyclic voltammetry results indicates that poly [ 3-(1-naphthylthiophene)] cannot be n-doped very efficiently in the exp erimental conditions used in this work.