SYNTHESIS AND PROPERTIES OF A SERIES OF METHYLTHIO OLIGOTHIOPHENES

A homologous series of donor-substituted oligothiophenes 7-9 bearing m ethylthio groups in the ''outer'' beta-positions were synthesized up t o a quaterthiophene. The physical properties are dependent on the chai n length of the conjugated system. The compounds exhibit biological ac tivites. Due to the substitution pattern, even the longer oligomers ex hibit good film-forming properties and could be electropolymerized to the corresponding donor-substituted polythiophenes P7-P9 with a stereo regular structure. The electronic properties were found to be dominate d by the donor strength of the substituents.