Linearly Tunable Emission Colors Obtained from a Fluorescent–Phosphorescent Dual‐Emission Compound by Mechanical Stimuli

Abstract

Organic mechanoluminochromic materials are mechano/piezo-responsive and promising for applications in sensors,d isplays,a nd data storage devices.H owever,t heir switching range of emission is seriously impeded by only one kind of emission (either afluorescent or phosphorescent peak) in the spectrum of single organic compounds.T his study presents ad esign strategy for pure organic compounds with excellent room-temperature fluorescent-phosphorescent dualemission (rFPDE) properties,w hich combines the effective factors of dipenylsulfone group,c rystalline state,a nd heavy atom effect. Following the principle of color mixing, myriad emission colors with aw ide range from orange to purple and across white zone in astraight line in the chromaticity diagram of the Commission Internationale de lEclairage (CIE) can be obtained by simply mechanical grinding the compound. The unique properties could be concentrated on ap ure organic compound through this design strategy,w hichprovides an ew efficient channel for the discovery of efficient mechanoresponsive organic materials.Controlling and tuning the solid-state luminescence of organic materials continues to be an attractive topic in both theoretical research and practical applications in the fields of sensing, [1] color displays, [2] and data storage. [3] Ther elationship in the molecular level between the emission properties of organic luminescent materials and the external pressure or mechanical stimuli has recently gained considerable attention because the knowledge of such ar elationship is essential to real-world applications of the "smart" materials. [4][5][6][7][8][9][10][11] Many studies have been conducted on mechano/piezo-responsive organic luminescent materials,a lso known as mechanoluminochromic materials.H owever,s tudies focusing on the switching range of the emission of such materials remain limited. [11,12] On the other hand, although the compounds are constructed with complex molecular structures,t hese single organic compounds generally exhibit only one kind of emission, either fluorescent or phosphorescent, in the solid state. [13] This limitation seriously impedes the extent of the switching range of such compounds.T hus,p ure organic molecules with room-temperature fluorescent-phosphorescent dual-emission (rFPDE) properties are essentially superior to the above-mentioned luminophores for mechanoluminochromic materials.G iven the difference between the radiative processes of fluorescence and phosphorescence,the separate dual emissions in rFPDE materials exhibit respectively tunable luminescent characteristics under external stimuli, [14] which significantly enrich their emission switching. We present in this communication as uccessful strategy to obtain new rFPDE materials with al arge separation in their dual emissions from asingle organic compound ( Figure 1A). When the crystals of the rFPDE organic compound were converted into the amorphous powder by mechanical stimulus,the compound exhibits an unusually wide range of blue shift in its emission fr...

Development of a New Multiple Stimuli-Responsive Fluorescent Material Using the Minus Strategy Based on the Structure of Tetraphenyl-1,3-butadiene

“…The endothermic transition peak recovered when the ground L1 sample was heated or immersed in acetone. 37 , 38 …”

“…The endothermic transition peak recovered when the ground L1 sample was heated or immersed in acetone. 37,38 Based on their mechanochromic properties, we explored a practical application of L1 in a rewritable paper. As shown in Figure 3d, the pristine powder of L1 was applied on a piece of weighing paper.…”

Achieving Molecular Fluorescent Conversion from Aggregation-Caused Quenching to Aggregation-Induced Emission by Positional Isomerization

“…The endothermic transition peak of the sample immersed in acetone showed no change, but a glass transition appeared at 393.5 °C [ 36 , 37 , 38 ]. However, the DSC curves of PDB4 did not exhibit properties similar to PDB2 [ 39 ]. There was no significant change in the DSC curve of PDB4.…”

Time‐ and Excitation Wavelength‐ Dependent Afterglow Supramolecular Assembly for Multi‐Modal Anti‐Counterfeiting Application

“…[6][7][8][9][10] Importantly, the change in emission lifetime under external stimuli could be considered as another visual monitoring parameter in addition to emission color and intensity, which would empower this kind of material additional encryption modes in anticounterfeiting and data encryption. [11][12][13][14][15] In recent years, heatingresponsive, [16][17][18] pH-responsive, [19][20][21] and force-responsive afterglow materials [22][23][24] have been explored. However, these systems relying on invasive external stimulus are not only harmful to the materials, but also inconvenient to operate for consumers without professional chemistry knowledge.…”