Synthesis, Photophysical, and AIE Properties of 2H-Imidazole-Derived Push-Pull Fluorophores

Abstract

A four-stage method for the synthesis of 2H-imidazole-derived push-pull fluorophores was developed. The synthesized compounds are characterized by absorption in the range of 250–400 nm, emission of up to 617 nm, and quantum yields of up to 99%. Compounds bearing a tetraphenylethylene fragment demonstrated the AIE effect in a solution with a water fraction fw >90% and significant increase in the emission intensity of up to 20 times and quantum yields of up to 22%. The ICT states for these fluorophores were confirmed by calculating the excited state dipole moments (>23D). The reported synthetic method enables fine-tuning of the fluorescent properties for the developed photoactive molecular systems by varying donor fragments. The obtained compounds could be of particular interest in the design of photoactive organic and hybrid materials.