Reversible Switching of the Emission of Diphenyldibenzofulvenes by Thermal and Mechanical Stimuli

Abstract

The thermochromic and mechanochromic fluorescence of diphenyldibenzofulvenes is investigated. Emission is boosted and blue‐shifted upon crystallization. Yellow emissive crystals of the material transform to green fluorescent crystals upon heating before melting. Reversible switching of the emission color and efficiency are achieved by repeated amorphization and crystallization of dye molecules by a pure thermal process or grinding–heating cycles.

Design amphiphilic dipolar π-systems for stimuli-responsive luminescent materials using metastable states

“…Recently, luminescent materials that are responsive to mechanical stimuli have attracted considerable attention because they have the unique ability to tune their molecular, physical or chemical properties via macroscopic stimulation [5][6][7][8] . Several mechanistic explanations for the mechanically stimulated changes in the colour of the luminescence have been proposed: a phase transformation of the solid structure [9][10][11][12][13][14][15][16] , excimer formation or dissolution [17][18][19] and mechanical stress-induced chemical changes 20,21 . However, the development of new materials with luminescent mechanochromism still depends heavily on serendipitous discovery or random screening; studies based on rationally designed luminophoric compounds and sensitivity to mechanical stimuli remains rare.…”

Design, Synthesis and Characterization of Triarylacrylonitrile Compounds Exhibiting Aggregation-Induced Emission and High Contrast Reversible Mechanochromism

“…随后, 一些其他的具有力致变色的 AIE 化合物 被报道, 例如, 具有烷基链或苯基的二苯基二苯芴乙 烯 [34,35] , 具有咔唑或烷基链的四苯乙烯 [36,37] , 苯丙烯 腈 [38,39] 和二乙烯蒽衍生物 [40～42] . 这些研究表明具有高 度扭曲立体构型的共轭分子是潜在的新型力致变色性 能 AIE 材料的候选者 [8] .…”

Nanophotonics and supramolecular chemistry

“…A mechanically induced conversion from crystalline to amorphous induces a molecular rearrangement which permits greater rotational freedom to form excimeric or intermolecular charge-transfer species. Dong, Tang, and coworkers reported unusual aggregation-induced emission for diphenyldibenzofulvene molecules 13 [74].…”