A semiempirical study of heterocycle oligomers and polymers in different dielectric media

Four common five‐membered heterocycles—pyrrole, phosphole, thiophene, and furan—and their oligomers with the chain length of 2, 4, 6, and 10 units have been studied quantum chemically using the semiempirical PM 3 parameterization. The oligomers of pyrrole and phosphole with the homolytically dissociated NH bond and PH bond, respectively, and oligomers of thiophene and furan with one electron removed per monomer unit (4 n + 2 π‐electron bipolaron systems) have also been studied. The electronic properties of the respective polymers were extrapolated from the oligomer data. Bulk polymer effects on the electronic structure were modeled using the self‐consistent reaction field theory in the multicavity approximation ( MC a SCRF ).