Synthesis of aza-analogues of poly(isothianaphthene)

The reaction of phthalic anhydride with phosphorus pentasulfide which gives poly(isothianaphthene) (PITN) has been extended to some other anhydrides and its derivatives (phthalimides and phthalhydrazide). The reaction with anhydrides leads to polymers, while the reaction with other derivatives can lead to thio, dithio compounds or polymers. Contrary to theoretical predictions, aza-analogues of PITN do not seem to have better electrical properties. The most conductive is polyisoindol with conductivity of 10−4 S/cm, which is still 100 times lower than PITN synthesized under similar conditions.