Effect of crosslinking patterns on the properties of conjugated microporous polymers

Syntheses and detailed spectroscopic characterizations of two similar conjugated microporous polymers formed by A4 + B2 and A2 + B3 type functional monomers via Sonogashira-Hagihara polycondensation are presented in this report. The two porous polymeric networks possess mono-, di-, and tri-(1-, 1,4-, and 1,3,5-, respectively) substituted benzene rings and fused thiophenic moieties (dithienothiophenes). Because of the different conjugation patterns, their solid state nuclear magnetic resonance, infrared, and ultraviolet/visible light absorption analyses indicated significant differences. Besides the discussions on the porous properties of the obtained polymeric networks, the presented spectroscopic investigations can be useful for identifying the structure-property relationship of the novel conjugated porous polymeric structures, since the characterization of such nonsoluble compounds by using fundamental techniques is always a challenge.