Reduction of the steric hindrance to conjugation in 3,4-disubstituted poly(thiophenes); cyclopenta[c]thiophene and thieno[c]thiophene as precursors of electrogenerated conducting polymers

The cyclopenta[c]thiophene (1) and thieno[c]thiophene (2) have been synthesized and used as substrates for electropolymerization; steric hindrances is less in poly(1) than in poly(3,4-dialkylthiophenes), while attempts to electropolymerize (2) were unsuccessful.