Aqueous-phase tunable multi-color luminescent supramolecular assemblies based on cucurbit[10]uril-enhanced intermolecular charge-transfer interactions

Abstract

The construction of tunable multi-smart luminescent materials induced by noncovalent supramolecular interactions has become one of the most important topics in luminescent materials research. Herein, we report novel tunable multi-color luminescent supramolecular assemblies based on cucurbit[10]uril (CB[10])-enhanced noncovalent heterodimer intermolecular charge-transfer interactions. Through host-enhanced homodimer intermolecular charge-transfer interactions, the addition of CB[10] promoted the enhancement of green, yellow, and red fluorescence emission of anthracene derivatives G1, G2, and G3 (as electron donor guests). When the electron acceptor azaanthracene G4 was introduced into the host–guest solution of G1–G3 and CB[10], interesting color changes from blue to green, yellow and red were observed due to the enhancement of host-enhanced heterodimer intermolecular charge-transfer interactions. Interestingly, white-light emission with a high quantum yield φ_F of 42.48% was achieved when 0.8 equiv. of CB[10] were present in aqueous solution of equal amounts of G2 and G4, and a luminescence color conversion from white to light blue was achieved upon UV irradiation. Furthermore, the host–guest assembly with white emission exhibited light- and humidity-responsive properties when coated on a thin film, providing a handy and feasible strategy for the construction of tunable multi-smart luminescent materials.