Naphth[4]arene: Synthesis, Conformations, and Application in Color‐Tunable Supramolecular Crystalline Assemblies

Abstract

Although the chemistry of macrocyclic arenes has seen rapid development in recent years, the synthesis of new macrocyclic arenes from aromatic rings with no directing groups remains a challenge. In this work, a new macrocyclic arene, naphth[4]arene (NA[4]A), composed of four naphthalene rings bridged by methylene groups, was synthesized using macrocycle‐to‐macrocycle conversion. NA[4]A shows 1,3‐alternate and 1,2‐alternate conformations in the solid state, which can be selectively obtained. By supramolecular co‐assembly of NA[4]A and 1,2,4,5‐tetracyanobenzene (TCNB) in different concentrations and temperatures, two conformation‐dependent crystalline luminescent co‐assemblies 1,2‐NTC and 1,3‐NTC can be selectively prepared. Interestingly, the two charge‐transfer crystalline assemblies containing NA[4]A with different conformations show bright yellow and green fluorescence, and also display high photoluminescence quantum yields (PLQYs) of 45 % and 43 %. Furthermore, they exhibit color‐tunable two‐photon excited upconversion emission.

Temperature-Responsive Cocrystal Engineering for Efficacious Delivery of Poorly Water-Soluble Herbicide

“…As is widely recognized, cocrystal engineering design leverages the supramolecular assembly strategy in solid-state chemistry, primarily encompassing two aspects: the type of supramolecular synthon and the conformation of molecules. While the former serves as the foundational framework for forming a three-dimensional hydrogen-bond network, the latter essentially buttresses the former. − …”

Hydrophilic Cocrystals with Water Switched Luminescence

“…[4][5][6] Organic cocrystals comprise two or more different compounds with a specific stoichiometric ratio [7][8][9] which endows their photophysical characteristics can be easily tuned by regulating different intermolecular interactions, [10][11][12] solvents, [13][14][15][16] or external stimuli. [17][18][19][20] Particularly, the organic solvents can considerably affect the photophysical properties of OLCCs by regulating the molecular conformation and stacking of cocrystals [8,13,21,22] and can even be directly used as a guest in forming cocrystals. [7,14,15] Hu et al presented a novel ternary solvated cocrystal (perylene-TCNB) • 2THF, which could undergo reversible transformation into a binary perylene-TCNB cocrystal via the successive desorption of the tetrahydrofuran (THF) solvent.…”

Hydrophilic Cocrystals with Water Switched Luminescence

“…[4][5][6] Organic cocrystals comprise two or more different compounds with a specific stoichiometric ratio [7][8][9] which endows their photophysical characteristics can be easily tuned by regulating different intermolecular interactions, [10][11][12] solvents, [13][14][15][16] or external stimuli. [17][18][19][20] Particularly, the organic solvents can considerably affect the photophysical properties of OLCCs by regulating the molecular conformation and stacking of cocrystals [8,13,21,22] and can even be directly used as a guest in forming cocrystals. [7,14,15] Hu et al presented a novel ternary solvated cocrystal (perylene-TCNB) • 2THF, which could undergo reversible transformation into a binary perylene-TCNB cocrystal via the successive desorption of the tetrahydrofuran (THF) solvent.…”

“…Organic cocrystals comprise two or more different compounds with a specific stoichiometric ratio [7–9] which endows their photophysical characteristics can be easily tuned by regulating different intermolecular interactions, [10–12] solvents, [13–16] or external stimuli [17–20] . Particularly, the organic solvents can considerably affect the photophysical properties of OLCCs by regulating the molecular conformation and stacking of cocrystals [8,13,21,22] and can even be directly used as a guest in forming cocrystals [7,14,15] . Hu et al.…”