One Stimulus In Situ Induces Two Sequential Luminescence Switchings in the Same Solvent‐Fuming Process: Anthracene Excimer as the Intermediate

Abstract

Commonly, one stimulus only induces one luminescence switching in stimuli-responsive experiment. Herein, it is reported that one stimulus in situ induces two luminescent switches, resulting from two phase transitions in a solvent-fuming process. Two phase transitions are in situ composed of a first fast and a subsequent slow process, corresponding to the change of molecular packing from the amorphous state to the π-π dimer crystalline state to the cocrystalline state with the inclusion of solvents, accompanied with luminescent transformation from pure blue to green to deep blue. Theoretical and experimental results reveal that the staggered π-π dimer stacking of anthracenes serves as the intermediate state to bridge the two phase transitions. This finding expands a new horizon in the stimuli-responsive field and inspires novel applications in information storage and security fields.

Design of High-Contrast Mechanochromic Materials Based on Aggregation-Induced Emissive Pyran Derivatives Guided by Polymorph Predictions

“…The development of stimuli-responsive organic fluorescent materials has received tremendous attention as a result of their fundamental research and promising applications in information storage, 1,2 anti-counterfeiting paper, 3,4 sensors [5][6][7] and bioimaging. [8][9][10] In particular, mechanochromic (MC) materials that use mechanical force as a stimulus have been recognized as ideal candidates for preparing anti-counterfeiting labels and pressure-sensitive devices.…”

Deep-red electro-fluorescence based on an excimer emission with hot-exciton channels

“…Despite the fact that the aggregates, especially the excimer and exciplex, that are used are believed to be of low-efficiencies, recently, our group have reported a series of highly efficient excimer fluorescent materials. [9][10][11] For example, with systematically regulated side-group substitutions, the optimized structure 2-(anthracen-9-yl) thianthrene (2-TA-AN) exhibits a green excimer emission at 526 nm with a considerably high PLQY of 80% compared with its deep-blue, but low-efficiency monomer emission (424 nm, PLQY = 33%). 12 However, the present excimer is that the molecular structure of these efficient excimers is limited to anthracene derivatives, which can only produce a green emission.…”

Tricolor fluorescence switching in the three crystal polymorphs of tetraphenylethylene modified fluorenone AIEgen

“…30 With further studies of the AIE effect, a large number of AIE molecules have been found to exhibit stimulus-responsive fluorescence switching characteristics, which greatly promotes the development of organic solid-state fluorescent materials. 26,[31][32][33][34][35][36] Nevertheless, most of the reported examples display a reversible two-color luminescence switching, and multicolor switching materials remain extremely scarce due to the un-designability of these kinds of smart materials. Moreover, the successful cases that can clearly illuminate the luminescence switching mechanisms are very few because the metastable state is hard to control and obtain, resulting in the absence of structural evidence (X-ray crystal structures).…”