Poly , arene polycondensation

The application of Heck coupling polycondensation is not limited to the synthesis of poly(arylene vinylene)s via the alkenylation of haloarenes in simple monomer systems but includes a variety of self- and cross-coupling reactions involving reactants with various functionalities. For instance, the polycondensation of diiodoarene with bis(acrylamido)arene by the Pd(OOCCH3)2—P (o-C6H4—CH3)3 catalyst yields respective aromatic polycinnamamide [106] ... 

The key initiation step in cationic polymerization of alkenes is the formation of a carbocationic intermediate, which can then interact with excess monomer to start propagation. The mechanism of the initiation of cationic polymerization and polycondensation has been extensively studied. Trivalent carbenium ions play the key role, not only in acid-catalyzed polymerization of alkenes, but also in poly condensation of arenes (n -bonded monomers), as well as in cationic polymerization of ethers, sulfides, and nitrogen compounds (nonbonded electron-pair donor monomers). Pentacoordinated carbonium ions, on the other hand, play the key role in the electrophilic reactions of a-bonds (single bonds), including the oligocondensation of alkanes and the cocondensation of alkanes and alkenes. 

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