Block and Random Living, Ring-Opening Metathesis Copolymerization of Functionally Differentiated Carbazole-Containing Norbornene Monomers

Abstract

The synthesis of novel diblock polymers containing both a potential charge transport and a non-linear optic block has been accomplished. The synthesis exploits the living, ring-opening metathesis block copolymerization of two norbornene type monomers, one of which contains an unsubstituted N-carbazolyl ring while the other has a bromo substituent at the 3-position of the carbazole ring. Conversion of the bromo functionality to a 2,2-dicyanovinyl group introduces the non-linear optic property. The first monomer was prepared by the previously reported efficient cation radical Diels–Alder cycloaddition of N-trans-1-propenylcarbazole to 1,3-cyclopentadiene, while the second was obtained by N-bromosuccinimide bromination of the first monomer. For purposes of comparison, the corresponding random copolymer was also synthesized.