Conducting Polymers from 3,4‐Disubstituted Polypyrroles

Pyrrole derivatives, which were substituted in the 3,4‐position by a fused alkyl ring have been synthesized and their electrochemical and electrical properties have been investigated. — Compounds with a five, six, seven and twelve membered ring fused to the pyrrole moity were obtained by means of a 3 + 2 cycloaddition of tosylmethylisocyanide to an α,β‐unsaturated ketone. Electrooxidation in acetonitrile/ tetrabutylammonium perchlorate led to the deposition of brittle, black, conducting polymer films on the anode, which could be reversibly reduced and reoxidized in the range of +1 to −1 [V] vs. Ag/Ag + . The electrodeposited films swell in polar aprotic media. — The conductivity decreased with increasing ring size of the substituent from 0.4 S cm −1 (five membered ring) to 2 ± 10 −4 S cm −1 (twelve membered ring), while the temperature dependence increased. — The polypyrrole derivative containing the twelve membered ring showed a strong frequency dependence of the conductivity at 100 K. By changing the frequency from 0.01 to 1000 KHz the conductivity increased by two orders of magnitude.