Cucurbit[n]uril‐Based Supramolecular Frameworks Assembled through Outer‐Surface Interactions

Abstract

Porous materials, especially metal–organic frameworks, covalent organic frameworks, and supramolecular organic frameworks, are widely used in heterogeneous catalysis, adsorption, and ion exchange. Cucurbit[n]urils (Q[n]s) suitable building units for porous materials because they possess cavities with neutral electrostatic potential, portal carbonyls with negative electrostatic potential, and outer surfaces with positive electrostatic potential, which may result in the formation of Q[n]‐based supramolecular frameworks (QSFs) assembled through the interaction of guests within Q[n]s, the coordination of Q[n]s with metal ions, and outer‐surface interaction of Q[n]s (OSIQ). This review summarizes the various QSFs assembled via OSIQs. The QSFs can be classified as being assembled by 1) self‐induced OSIQ, 2) anion‐induced OSIQ, and 3) aromatic‐induced OSIQ. The design and construction of QSFs with novel structures and specific functional properties may establish a new research direction in Q[n] chemistry.

The binding behaviours between cyclopentanocucurbit[6]uril and three amino acids

“…The introduction of CdCl 2 or ZnCl 2 into aqueous HCl solutions can produce [CdCl 4 ] 2− or [ZnCl 4 ] 2− etc. anions which is helpful to prepare various Q[ n ]-based single crystals owing to the outer surface interaction formed between these anions and the electrostatic potential positive outer surface of Q[ n ]s [ 2 , 32 – 33 ].…”

Dual catalytic activity of a cucurbit[7]uril-functionalized metal alloy nanocomposite for sustained hydrogen generation: hydrolysis of ammonia borane and electrocatalysts for the hydrogen evolution reaction

“…12,[24][25][26][27][28] Cucurbit [7]uril (CB7), one of the homologues of the CB family, comprises seven glycoluril units and shows strong interaction towards cations/metal ions through ion-dipole interactions, moderate interaction towards organic guest molecules through hydrophobic interactions and the positively charged carbon centers on the equatorial region of CB show interactions towards polyanions. 12,[24][25][26][27][28][29][30][31][32][33] By capitalizing on such subtle non-covalent interactions, in an earlier study, we achieved the separation of clinical grade radioactive technetium ( 99m Tc) for theranostic purposes. 29 In a recent study on the metal-free catalytic hydrolysis of AB using CB hosts as catalysts at room temperature, we have established an enhanced hydrolysis reaction rate, lowering the activation energy and significant decrease in ammonia release.…”

Fluorescent Molecular Cages with Sucrose and Cyclotriveratrylene Units for the Selective Recognition of Choline and Acetylcholine

“…The synthesis of molecular cages is particularly attractive due to its selective recognition properties. 5 These receptors can find application as catalysts, 6 separators, 7 sensors, 8 porous materials, 9 polymers, 10 transporters, 11 or drug delivery systems. 12 Among them, cryptophanes and hemicryptophanes are of particular interest as they are able to recognize small organic compounds.…”