Synthesis and two-photon absorption properties of a red-emitting poly(2,6-anthracenevinylene) derivative with donor–acceptor–donor motif

A novel poly(2,6-anthracenevinylene) derivative (Pr) with donor–acceptor–donor motif was synthesized by Witting reaction of 9,10-dicyano-2,6-bis(diethylphosphoryl-methyl)anthracene and 4,6-bis(bis(2-ethylhexyl)amino)isophthalaldehyde, and its one- and two-photon properties were investigated. Pr showed a number-average molecular weight of 11,360 by end-group analysis and 15,300 by GPC, respectively. The Pr solution in toluene exhibited a maximal absorption wavelength peaked at 591 nm with the onset wavelength of 690 nm and emitted a red fluorescence centered at 665 nm with a fluorescence quantum yield of 0.10. Pr exhibited the maximum two-photon absorption cross-section of 1430 g per repeating unit at 920 nm measured by two-photon-induced fluorescence method. The results indicate the polymers with large TPA cross sections can be obtained by employing effective TPA chromophores as the building blocks, and the wavelength of the maximal TPA for 2,6-anthracenevinylene-based polymers could be tuned by attaching appropriate donor and/or acceptor substituents.