Pressure-Induced Blue-Shifted and Enhanced Emission: A Cooperative Effect between Aggregation-Induced Emission and Energy-Transfer Suppression

Aggregation‐induced emission (AIE), as an exciting photophysical phenomenon, has been regarded as one frontier research topic within both ranges of molecular luminescence and materials science over the last two decades. Since controllable molecular ensembles with particular morphologies and tunable functions can be elegantly constructed in the realm of supramolecular chemistry, the integration of supramolecular assembly and AIE systems can expectedly bring about luminescent materials with tunable emission and tailorable well‐ordered architectures. In this review, we will provide a summary of the creation and working mechanisms of AIE systems involving supramolecular systems that are driven by different supramolecular driving forces including hydrogen bonding, host−guest interactions, metal coordination, and π–π interactions. The morphological and photoluminescent features of these AIE‐active supramolecular assemblies will be elucidated, and the regulated fluorescence properties of the AIEgens induced by the assembling–disassembling processes will be discussed in detail.

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Section: Aie Systems Involving–interaction–driven Supramolecular Assementioning

confidence: 99%

Aggregation‐induced emission systems involving supramolecular assembly

Lou

Yang

2020

Aggregate

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“…Synthetic difficulties involving expensive catalysts and harsh conditions have made access to such molecular materials challenging [6] . A few MFC materials such as carbon dots [7a] and π‐conjugates [7b] with blue‐shifted emission have also recently been developed. Apart from one earlier report on charge‐transfer cocrystals, with 33 nm blue‐shifted MFC upon anisotropic grinding, [6a] we now present a first P=O⋅⋅⋅H interaction directed cocrystal exhibiting the highest blue‐shifted (2087 cm −1 ) mechanofluorochromism.…”

Section: Figurementioning

confidence: 99%

Mechanofluorochromic Anthryl Phosphonate/Benzoic Acid Cocrystals with a Large Blue Shift: The Role of P=O⋅⋅⋅H Interactions

Prusti

Chakravarty

2020

ChemPlusChem

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Organophosphonates have a rich and diverse chemistry, but their mechanofluorochromic features have rarely been documented. Herein, we report on cocrystals of anthranylphosphonate with (E)‐4‐(2‐(anthracen‐9‐yl)vinyl)benzoic acid that exhibit reversible mechanofluorochromic properties with large blue shifts. Anisotropic grinding (or pressure of just 25 kPa) maintains the co‐crystals emission features but leads to a pronounced 59 nm (2087 cm−1) blue‐shift. Such an impressive blue‐shift for a cocrystal has not been reported to date. The underlying causes for the blue‐shift were validated by X‐ray diffraction (powder and single crystal) studies and Hirshfeld surface analysis. Twisted molecular conformations and P=O⋅⋅⋅ H/C=O⋅⋅⋅H/C⋅⋅⋅H noncovalent interactions afford molecular arrangements via slip‐stacks with two different pitch angles and relatively larger interlayer distances. The new compound was established as a potential medium for optical recording and security display.

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“…33 Integrating anthracene with tetraphenylethyelene (TPE) showed pressure induced enhanced blue shifted fluorescence by suppressing energy transfer. 34 TPE based donor (D)-acceptor (A) materials showed molecular structure dependent pressure induced fluorescence enhancement. 9,29,[35][36][37][38][39] Introducing alkyl chain resulted selfreversible MFC materials and super-cooled fluorescent liquid.…”

Section: Introductionmentioning

confidence: 99%