A new, low band‐gap polymer (see figure), a hybrid of polythiophene and polyisothianaphthene, has been synthesized. Current interest in the synthesis of low bandgap polymers is considerable in view of their potentially superior conductivity and nonlinear optical properties. The results complement well the independent analogous work reported by Bäuerle et al. in the following article. (Figure Presented.) Copyright © 1992 Verlag GmbH & Co. KGaA, Weinheim