Controlled electrochemical synthesis of poly(3-octylthiophene) considering analytical applications

: Niu L, Kvarnstrom C, Ivaska A

Publisher: POLSKIE TOWARZYSTWO CHEMICZNE-POLISH CHEMICAL SOCIETY

: 2005

: Chemia Analityczna

: CHEMIA ANALITYCZNA

: CHEM ANAL-WARSAW

: 50

: 1

: 139

: 153

: 15

: 0009-2223

Poly(3-octylthiophene) was electrosynthesized galvanostatically and characterized electrochemically, by electrochemical quartz crystal microbalance and by in situ resonance Raman spectroscopy. Results from mass spectroscopy show that oligomers consisting of 3, 4, and 5 units were produced and trapped into the polymer film. H-1 NMR measurement confirmed the regioregular structure of these oligomers. The applied current densities (> 0.26 mA cm(-1)) during electrosynthesis played a predominant role on the content of regioregular oligomers in the film. Higher current densities were advantageous to the production of the oligomers; also lower monomer concentration (< 5 mmol L-1) promoted the formation of regioregular components. The thickness of the film was found to have minor influence on the content of the oligomers. Cyclic voltammograms of the formed films clearly show two well-separated pairs of reversible peaks representing two different charge transfer mechanisms, which can be derived from reduction/oxidation of the regioregular oligomers. The in situ Raman spectroscopic results show significant changes in the positions and intensities of the Raman bands upon oxidation.