ELECTROCHEMICAL POLYMERIZATION OF 3-OCTYLPYRROLE

Electrochemical polymerization of 3‐octylpyrrole (OCPY) yielded a film on the anode. Its conductivity was 5 S/cm. Infrared spectra of OCPY and poly(3‐octylpyrrole) (POCPY) were compared with those of related monomers and polymers, and as a result, the pyrrole rings appeared quite likely linked at 2‐ and 5‐positions. Cyclic voltammograms of a PF–6‐doped POCPY film had an anodic peak at 0.16 V vs. Ag and a cathodic peak at 0.12 V. Doped POCPY was stable and soluble in such polar solvents as tetrahydrofuran, N‐methylpyrrolidinone and pyridine. Although the absorption spectrum of the film had three peaks at 1.0, 2.5 and 3.6 eV, as also in the case of poly(3‐methylpyrrole), the spectra in pyridine and THF solutions indicated two peaks at 1.9 and 3.2 eV. Scanning electron microscopy (SEM) showed the POCPY films to have a unique morphology, depending on the electrolytes used for electrochemical polymerization. The introduction of an octyl group made polypyrrole soluble in organic solvents, but effective conjugation length became shorter and the texture of films rougher. Copyright © 1990 John Wiley & Sons, Inc.