Palladium-Catalyzed Cross-Coupling Polymerization: A New Access to Cross-Conjugated Polymers with Modifiable Structure and Tunable Optical/Conductive Properties

While the synthesis of conjugated polymers has received significant attention, the preparation of cross-conjugated polymers, where the π-electron delocalization cannot extend along the backbone, has received much less success. We have exploited a new catalytic polymerization process and developed the Pd-catalyzed cross-coupling enabled synthesis of cross-conjugated polymers with readily accessible N -tosylhydrazones and aryl halides. A broad scope of cross-conjugated polymers with good processability and thermal stability has been prepared in high yields using dialkylbiarylphospine–Pd precatalysts. Owing to their unique vinyl structures, these polymers could be easily modified in postpolymerization fashions to impart high degrees of structural complexities. Moreover, these materials were shown to have interesting and tunable optical and conductive properties, featuring their great potentials in a variety of applications.