Tuning solid-state emission properties of pyrene-containing chalcone derivatives

The synthesis and optical properties of chalcone dyes containing pyrene as a donor is described both in solution and in solid-state. With such molecules, we show that, while the ground-state dipole moment is almost zero, the excited state is highly polar resulting in an intramolecular charge transfer excited state. All the chalcone molecules were shown to be emissive in the solid state but the behavior is different as a function of the substituent appended on the aryl group connected to the carbonyl function of the chalcone. We evidenced the beneficial effect of a methoxy function on the aggregation yielding an enhancement of the emission quantum yield in solid-state as compared to the solution. (C) 2015 Elsevier Ltd. All rights reserved.