Synthesis of Conjugated Polymers Containing Octafluorobiphenylene Unit via Pd-Catalyzed Cross-Dehydrogenative-Coupling Reaction

Abstract

Polycondensation via Pd-catalyzed cross-dehydrogenative-coupling reaction of 2,2',3,3',5,5',6,6'-octafluorobiphenyl with thiophene analogues was studied. The synthetic protocol, in which employment of prefunctionalized starting monomers was fully avoided, allowed straightforward access to an alternating π-conjugated polymer. The addition of K₂CO₃ to the catalytic system promotes the cross-coupling reaction and suppresses the undesired homocoupling reaction, producing the corresponding donor-acceptor type π-conjugated polymers with minor homocoupling defects. The reaction also proceeded using O₂ as the terminal oxidant, resulting in lower loading of the Ag oxidant. The obtained polymer was evaluated as an emitting material for an organic light-emitting diode.