Multistimuli Response and Polymorphism of a Novel Tetraphenylethylene Derivative

Abstract

Multi-stimuli-responsive fluorescent molecule tetraphenylethylene (TPE) derivative 1 is synthesized, which contains a TPE skeleton and peripheries of two methoxyl groups and one carboxyl group. It shows a typical aggregationinduced emission behavior and also exhibits fluorescence responses to pH change and amine vapors, and multicolored mechanochromic properties. The emission of 1 can be reversibly switched among blue (1p-f, 462 nm, Φ f = 7.4%), bright cyan (1p-h, 482 nm, Φ f = 82.3%), and yellow (1p-g, 496 nm, Φ f = 10.5%) with high contrast through solvent fuming, heating, or grinding. Molecule 1 occurs in four crystalline states (1c-a, 1c-b, 1c-c, and 1c-d) after crystallization from different solvents. The multicolored mechanochromic property is related to the different interactions and packing modes of molecules in the crystals. The crystals with weak fluorescent emission have characteristic porous structures and corresponding intensive XRD diffraction peaks, which are absent in the crystal with intensive fluorescent emission. The porous structures are critical for the fluorescence intensity of the molecules. Upon heating, the porous structures of crystals are damaged and fluorescence is significantly enhanced.

Aggregation‐Induced Emission Properties of Copper Iodide Clusters

“…[6,[20][21][22] The term piezofluorochromica ggregation-induced emission (PAIE) was even introduced. [23] Many pure organic mechanochromic materials with AIE-activem olecules were thus reported, [24][25][26][27][28][29][30][31] along with organoboron complexes. [32,33] Regarding metal-based compounds that combine AIE and mechanochromic properties, few studies have been reported, with examplesb ased on iridium(III), [34][35][36][37][38][39] cadmium(II), [40] zinc(II), [41,42] and gold(I) [43] complexes.…”

Reversible Crystal‐to‐Crystal Phase Transitions with High‐Contrast Luminescent Alterations for a Thermally Activated Delayed Fluorescence Emitter

“…In other words, crystal‐R had a much tighter packing mode than crystal‐Y. [ 21 ] The nonradiative transitions could thus be suppressed to some extent, which was in accordance with the fact that crystal‐R had a higher Φ PL than crystal‐Y. [ 22 ]…”

“…In other words, crystal-R had a much tighter packing mode than crystal-Y. [21] The nonradiative transitions could thus be suppressed to some extent, which was in accordance with the fact that crystal-R had a higher Φ PL than crystal-Y. [22] Differential scanning calorimetry (DSC) measurements were carried out to further explore the phase transition behavior.…”

A self-healing supramolecular hydrogel with temperature-responsive fluorescence based on an AIE luminogen

“…Recent research has shown that many AIE phenomena rely on surface adsorption, self-assembly, crystallization, polymerization, etc. [23][24][25][26][27][28] Besides, some groups reported the monitoring of the transition temperature by introducing AIE units into polymer chains, which illustrated the potential application of the AIE units as uorescent probes. For example, Bao et al developed a sensitive and reliable approach for the detection of the glass transition temperature (T g ) of polymers using tetraphenylethene derivatives as uorescent sensors; 29 Yang and coworkers proposed an efficient method to measure the topology freezing transition temperature (T v ) of a vitrimer by the uorescence change in the AIE molecules; 30 Wang et al reported enhanced uorescence emission around the lower critical solution temperature (LCST) by importing the AIE property into the thermo-responsive polymer.…”