Importance of the Order of Successive Catalyst-transfer Condensation Polymerization in the Synthesis of Block Copolymers of Polythiophene and Poly(p-phenylene)

Successive catalyst-transfer condensation polymerization of a Grignard-type phenylene monomer and then a thiophene monomer with a Ni catalyst yields well-defined block copolymers of poly(p-phenylene) and polythiophene, but the reverse order of polymerization results in polymers with broad molecular weight distribution.