Star-shaped D-π-A compounds with a 1,3,5-triazine core and N-aryl chromophore substituted fluorene arms: Synthesis, aggregation induced emission and two-photon absorption

Three star-shaped D-pi-A compounds with a 1,3,5-triazine core and N-aryl chromophore (3,6-di-tert-butylcarbazole, phenoxazine and phenothiazine) substituted fluorene arms were designed and synthesized. Their photophysical properties were investigated systematically via spectroscopic and theoretical methods. All compounds exhibit strong (1)pi-pi* transitions in the UV region and intense (1)pi-pi*/intramolecular charge transfer ((ICT)-I-1) absorption bands in the UV-vis region. Bathochromic shifts of the (ICT)-I-1 bands were caused by the electron-donating N-aryl chromophores. All compounds exhibit aggregation induced emission properties in asolvent, and relatively high quantum efficiency in solid-states (Phi = 10% -20%). Moreover, these compounds show two-photon absorption (TPA) properties due to their good planarity and large pi-conjugation. The largest TPA cross section value reaches up to 5000 GM at 800 nm. The multifunctional properties make these compounds potential candidates for application in organic light-emitting materials and two-photon bioimaging. (C) 2016 Elsevier Ltd. All rights reserved.