Solvent-Dependent Aggregation, Fluorescence Enhancement, and Supramolecular Chirality Inversion in Tetraphenylethylene-Based Assemblies.

Controlling fluorescence and chiroptical responses within one self-assembly system is of considerable interest. In this work, a chiral tetraphenylethylene derivative containing glutamic acid units was studied in dimethylformamide/water mixed solvents. With increasing water fraction, the molecules gradually aggregated and showed markedly enhanced fluorescence emission, characteristic of aggregation-induced emission behavior. At the same time, the assemblies displayed reversal of circular dichroism and circularly polarized luminescence signals, indicating solvent-dependent changes in supramolecular chirality in both the ground and excited states. Morphological and spectroscopic studies suggested that the optical changes were associated with variations in intermolecular interactions and aggregate packing. Molecular dynamics simulations further provided qualitative information on solvent-dependent aggregation and conformational variation of the assemblies. These results show a close correlation among aggregation, fluorescence enhancement, and chiroptical response in this chiral tetraphenylethylene-based system.