A photoluminescent molecular host with aggregation-induced emission enhancement, multi-stimuli responsive properties and tunable photoluminescence host-guest interaction in the solid state

The development of controllable multimodal luminescent materials that are responsive to external stimuli has been a challenge. In this study, a photoluminescent (PL) molecular host with aggregation-induced emission enhancement (AIEE) characteristic and multi-stimuli responsive properties has been designed, synthesized and its fluorescence response to mechanical, thermal, anion and guest stimuli have been studied in the solid state. Host 1 displays reversible tricolor-changing PL triggered by mechanical and thermal stimulations. Furthermore, anion exchange has demonstrated that the emission is affected by the anion size and the affinity between cation and anion moieties, resulting in enhancement or quenching effects. Additionally, grinding was used for inclusion of guests in the host molecular packing to tune the PL properties, most probably due to pi-pi interactions between molecular host and aromatic guests.