Fast and efficient one-pot ultrasound-mediated synthesis of solid state (full color tunable) fluorescent indolizine derivatives

We report herein an efficient, fast, and sustainable method for the preparation of fluorescent indolizine derivatives under ultrasound (US) irradiation using a one-pot and multicomponent methodology. In solution, the indolizine derivatives present absorption in the UV region and fluorescence emission in the violet-to-blue region with a relatively large Stokes shift. Aggregation-induced enhanced emission (AIEE) was observed in some derivatives by fluorescence studies in water/acetone systems. Regarding this particular property, the substituents showed to play a fundamental role. In the solid state, the derivatives present full-color tunable fluorescence also tailored by the substituents. Theoretical calculations using time-dependent density functional theory were performed to investigate the photophysics of these indolizine derivatives and were able to reproduce with accuracy their more prominent electronic features.

Automated summary

We developed an efficient and sustainable method for synthesizing fluorescent indolizine derivatives using ultrasound irradiation. These derivatives exhibit UV absorption and violet-to-blue fluorescence emission with a large Stokes shift. Some derivatives show aggregation-induced enhanced emission in water/acetone systems, which is influenced by the substituents. The solid-state derivatives also display tunable full-color fluorescence determined by the substituents. Theoretical calculations accurately reproduce the electronic features of these derivatives.