Electrodeposition of poly(indole-5-carboxylic acid) in boron trifluoride diethyl etherate containing additional diethyl ether

High quality poly(indole-5-carboxylic acid) (PICA) films were synthesized electrochemically by direct anodic oxidation of indole-5-carboxylic acid (ICA) in boron trifluoride diethyl etherate (BFEE) containing additional 80% diethyl ether (EE) (by volume). PICA films obtained from this medium showed good electrochemical behavior and good thermal stability with a conductivity of 10−2 S cm−1. The doping level of PICA increased during electrochemical growth processes. Dedoped PICA films were soluble in dimethyl sulfoxide (DMSO). The structure of the polymer were studied by UV–vis spectroscopy, FT-IR spectroscopy and 1H NMR spectroscopy, which indicated that the polymerization occurred at C(2) and C(3) position. Fluorescent spectral studies indicated that PICA was a good blue-light emitter.