Synthesis and Characterization of Donor–Acceptor Conjugated Microporous Polymer Films

The rational design of donor–acceptor (D–A) monomers enables control over porosity, electroactivity, and stability in conjugated microporous polymers (CMPs). Herein, we report the synthesis of five thiophene–benzothiadiazole-based monomers, four of them novel, and their polymerization via chemical (FeCl 3 oxidative) and electrochemical routes. Structural diversity was introduced through terthiophene regiochemistry (2,3- vs 2,4-substitution) and rigid, multibranched cores including benzene, spirobifluorene, and tetraphenylmethane. Chemically synthesized bulk CMPs exhibit specific surface areas of 81–591 m 2 g –1, while electropolymerized films from planar monomers suffer pore collapse. In contrast, rigid three-dimensional monomers yield smooth, highly porous films with surface areas up to 318 m 2 g –1 . The rigid structure of SpTBTTh enables the formation of thin polymer films with smooth morphology while preserving high porosity. Combined with favorable energy level alignment, these characteristics highlight the potential of rigid D–A CMP films as active layers in organic photovoltaic architectures.