Regioselective Synthesis of Thiophene-Based Poly(arylenevinylene)s via Co-Catalyzed Hydroarylation Polyaddition

Thiophene- based poly(arylenevinylene) is synthesized by the Co- catalyzed hydroarylation polyaddition of N,N,N',N'-tetrahexyl-(2,2'-bithiophene)-4,4'-dicarboxamide with 2,7-bis(4-ethynylphenyl)-9,9-di(n-octyl)fluorene in a regioselective manner. This reaction prevents the production of stoichiometric amounts of byproducts from the monomers. The amide substituents serve as directing groups for the Co catalyst to efficiently activate the C-H bonds at the 5,5'-positions of the bithiophene moiety. The polyaddition reaction yields the corresponding poly(arylenevinylene) with excellent vinylene selectivity. Site- and regioselective polyaddition reactions can also be performed for other aromatic diyne monomers containing electrondonating and electron-accepting units, which can alter the optical properties and energy levels of the polymers. The obtained poly(arylenevinylene)s work as semiconducting materials in organic light-emitting diodes and organic photovoltaics.