Novel A–π–D–π–A type molecules based on diphenylamine and carbazole with large two-photon absorption cross section and excellent aggregation-induced enhanced emission property

Abstract

A series of new A–π–D–π–A molecules including diphenylamine and carbazole had been synthesized and characterized (T1–T3). T1 and T2 displayed aggregation-induced emission enhancement (AIEE): exhibiting weak fluorescence in pure THF, which a signification AIEE effect was observed in mixture with a water fraction (fw) of 90% with a sharp increase in fluorescence intensity. T3 displayed aggregation-caused quenching (ACQ): exhibiting strong fluorescence in pure THF, which a signification ACQ effect was observed in mixture with a water fraction (fw) of 90% with a sharp decrease in fluorescence intensity. Their two-photon absorption (2PA) had been investigated using the open-aperture Z-scan technique, and the values of the 2PA cross section at 800 nm for T1–T3 were 1115, 681, in chloroform, respectively.