A general synthetic route towards soluble poly(1,3-dithienylisothianaphthene) derivatives

‘Formal’ copolymers consisting of bithiophene and aromatic isothianaphthene units, based on 1,3-dithienylisothianaphthene (DTI) derivatives, have been synthesized. The obtained materials have low band gaps and show high intrinsic conductivities. The polymers are obtained after oxidative polymerization of the corresponding DTI monomers with FeCl3. Solubilizing alkyl and thioalkyl side chains where introduced on different locations of the DTI skeleton. The substituents also influence the stability of the DTI monomers and the band gap of the polymers.