Donor-Acceptor Quateraryls: A Solution for the OLED Blues

Significance

The authors report the design and synthesis of a series of quateraryl blue emittors containing amine donor and cyano acceptor moieties. Their method serves as an improvement over previous polyaryl-substituted benzene syntheses that require iterative coupling reactions on sterically crowded substrates. The proposed mechanism of the final and key step involves Michael addition of the conjugate base of 5 to 4, followed by intramolecular cyclization, decarboxylation and dehydration. The analogues of 6 were used in the fabrication of multilayer light-emitting diodes.