An unprecedented cation radical chain Diels–Alder polymerization leading to novel carbazole polymers

The polymerization of 3,6-bis(trans-1′-propenyl)-N-phenylcarbazole in the presence of tris(4-bromophenyl)aminium hexachloroantimonate (1+) leads to soluble, high molecular weight, thermally stable cycloaddition polymers containing carbazole units in the main polymer chain. The reaction appears to proceed via a highly efficient cation radical chain mechanism which circumvents the usual hole transfer step of the propagation cycle. This polymerization represents the first observation of direct cation radical Diels–Alder cycloaddition polymerization.