AIE macrocyclic molecule-based assembled materials with opposite solvent-responsive properties

Abstract

Aggregation-induced emission (AIE) luminogen-based assembled materials usually exhibit excellent luminescence properties and have attracted widespread attention in chemical sensing, bioimaging, illuminated displays, etc. In this work, a butterfly-like AIE macrocyclic molecule of oxacalix[2]triphenylphosphine[2]pyrazine (OPpP) with multiple coordination sites was designed and synthesized using a simple two-step reaction. Due to the unique butterfly-like structure, OPpP exhibits typical AIE properties attributed to the restriction of intramolecular vibration (RIV) mechanism. Furthermore, combining OPpP with CuI, two luminescent assembled materials were constructed, which exhibit opposite solvent-responsive properties. A mechanism study showed that this phenomenon originated from the composite effect of RIV and intermolecular interactions caused by the absorption of solvent molecules. This work not only enriched the limited kind of RIV-type AIEgens, but also provided an ideal prototype for understanding the influence of molecule's intramolecular vibration on the luminescence properties of assembled materials.