BowtieArene: A Dual Macrocycle Exhibiting Stimuli‐Responsive Fluorescence

Abstract

Although highly useful in supramolecular chemistry, pillararenes lack a fluorophore in their skeleton. Here we present BowtieArene, a novel fluorescent dual macrocycle, featuring a central tetraphenylethylene‐derived fluorophore and two pillar‐like, pentagon‐shaped cavities which are comparable to pillar[5]arene. This concisely prepared, figure‐of‐eight molecule exhibits vapor absorption and host–guest capabilities, as well as intriguing switchable fluorescence. The fluorochromism of BowtieArene can be triggered by multiple external stimuli including solvent, vapor, and mechanical force, with excellent reversibility and stability. Experimental and theoretical evidence indicate that the fluorochromism should be closely related to molecular packing.

Structural Diversification of Pillar[n]arene Macrocycles

“…The final highlighted study demonstrates the combination of a tetraphenylethylene (TPE) fluorophore with two PA[5]s leading to the so‐called BowtieArene macrocyclic structure with multi‐stimuli‐responsive fluorescence, vapor absorption, as well as host–guest properties . Even though PA[ n ]s are very popular in supramolecular chemistry, they exhibit only slight fluorescence due to the absence of fluorophore units.…”

Strukturelle Diversifizierung von Pillar[n]aren‐Makrocyclen

“…Die letzte diskutierte Studie demonstriert die Kombination eines Tetraphenylethylen(TPE)‐Fluorophors mit zwei PA[5]s, die zu einer makrocyclischen “BowtieAren”‐Struktur mit multistimuliresponsiver Fluoreszenz, Dampfabsorption und Wirt‐Gast‐Eigenschaften führt . Obwohl PA[n]s in der supramolekularen Chemie sehr beliebt sind, zeigen sie aufgrund des Fehlens von Fluorophoreinheiten nur geringe Fluoreszenz.…”

Each phenyl group performs its own functions on luminescence: phenyl substituted effect in tetraphenylpyrazine

“…Organic p-conjugated fluorescent materials have been investigated in the past several decades owing to their promising applications in organic light-emitting diodes (OLEDs), [1][2][3][4][5][6] chemical sensors [7][8][9][10][11] and biological imaging. [12][13][14][15][16][17] However, the notorious problem of these classical luminescent materials is the familiar aggregation-caused quenching (ACQ), i.e., they weakly emit in their aggregated states such as powder and crystals compared to their dilute solutions.…”