Low-potential electrochemical polymerization of 5-fluoroindole and characterization of its polymers

Abstract High-quality poly(5-fluoroindole) (P5FIn) films were synthesized electrochemically by direct oxidation of 5-fluoroindole (5FIn) in pure boron trifluoride diethyl etherate (BFEE). The oxidation potential of 5FIn in this medium was measured to be only 1.05 V vs. SCE, which was much lower than that determined in acetonitrile + 0.1 mol L −1 Bu 4 NBF 4 (1.30 V). P5FIn films obtained from this medium showed good electrochemical behavior and good thermal stability. Dedoped P5FIn films were soluble in dimethyl sulfoxide. Fluorescent spectral studies indicate that P5FIn is a good blue-light emitter. The structure and morphology of the polymer were studied by UV–vis spectroscopy, FT-IR spectroscopy, 1 H NMR spectroscopy and scanning electron microscopy, respectively. The results of the spectroscopies of dedoped P5FIn indicated the polymerization mainly occurred at C (2) and C (3) positions.