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Abstract The accumulation of organic micropollutants (OMP) in aquatic systems is a major societal problem that can be addressed by approaches including nanofiltration, flocculation, reverse osmosis and adsorptive methods using insoluble materials (e.g. activated carbon, MOFs, nanocomposites). More recently, polymeric versions of supramolecular hosts (e.g. cyclodextrins, calixarenes, pillararenes) have been investigated as OMP sequestrants. Herein, we report our study of the use of water insoluble dimethylcatechol walled acyclic cucurbit[n]uril (CB[n]) hosts as solid state sequestrants for a panel of five OMPs. A series of hosts (H1–H4) were synthesized by reaction of glycoluril oligomer (monomer–tetramer) with 3,6‐dimethylcatechol and fully characterized by spectroscopic means and x‐ray crystallography. The solid hosts sequester OMPs from water with removal efficiencies exceeding 90 % in some cases. The removal efficiencies of the new hosts parallel the known molecular recognition properties of analogous water soluble acyclic CB[n]. OMP uptake by solid host occurs rapidly (≈120 seconds). Head‐to‐head comparison with CB[6] in batch‐mode separation and DARCO activated carbon in flow‐through separation mode show that tetramer derived host (H4)performs very well under identical conditions. The work establishes insoluble acyclic CB[n]‐type receptors as a promising new platform for OMP sequestration. 

Abstract We report the synthesis and X‐ray crystal structure of a cucurbituril–triptycene chimeric receptor (1). Host1binds to guests typical of CB[6]–CB[8], but also binds to larger guests such as blue box (20) and the Fujita square (22). Intriguingly, the geometries of the1⋅20and1⋅22complexes blur the lines between host and guest in that both components fulfill both roles within each complex. The fluorescence output of1is fully quenched by the formation of complexes with pyridinium‐derived guests. 

We report the synthesis of quaternary (di)cationic triamantane derivatives G1 and G3 by the permethylation of the corresponding primary ammonium ions G2 and G4. The complexation behaviors of G1–G4 toward CB[7] and CB[8] were examined by 1 H NMR spectroscopy, which reveals that CB[8] is capable of fully encapsulating G1–G4 whereas CB[7] forms inclusion complexes with G1, G2, and G4 but cannot fully encapsulate the central hydrophobic core of the bis-quaternary ammonium ion G3. The geometries of the CB[ n ]-guest complexes were determined by analyzing the complexation induced changes in chemical shifts and were further confirmed by molecular modelling using the Conformer–Rotamer Ensemble Sampling Tool (CREST) based on the GFN methods. Finally, the complexation thermodynamics were determined by a combination of 1 H NMR competitive experiments, direct isothermal titration calorimetry (ITC) measurements, and competitive ITC titrations using a tight binding ternary complex as a competitor. 

We report preparation of (bis)aniline ligand 4 which contains a central viologen binding domain and its subcomponent self-assembly with aldehyde 5 and Fe(OTf)2 in CH3CN to yield tetrahedral assembly 6. Complexation of ligand 4 with CB[7] in the form of CB[7]•4•2PF6 allows the preparation of assembly 7 which contains an average of 1.95 (range 1-3) mechanically interlocked CB[7] units. Assemblies 6 and 7 are hydrolytically unstable in water due to their imine linkages. Redesign of our system with water stable 2,2’-bipyridine end groups was realized in the form of ligands 11 and 16 which also contain a central viologen binding domain. Self-assembly of 11 with Fe(NTf2)2 gave tetrahedral MOP 12 as evidenced by 1H NMR, DOSY, and mass spectrometric analysis. In contrast, isomeric ligand 16 underwent self-assembly with Fe(OTf)2 to give cubic assembly 17. Precomplexation of ligands 11 and 16 with CB[7] gave the acetonitrile soluble CB[7]•11•2PF6 and CB[7]•16•2PF6 complexes. Self-assembly of CB[7]•11•2PF6 with Fe(OTf)2 gave tetrahedron 13 which contains on average 1.8 mechanically interlocked CB[7] units as determined by 1H NMR, DOSY, and ESI-MS analysis. Self-assembly of CB[7]•16•2PF6 with Fe(OTf)2 gave cube 13 which contains 6.59 mechanically interlocked CB[7] units as determined by 1H NMR and DOSY measurements. 

The efficiency and scope of two acyclic π-wall extended cucurbiturils, M2 and M3 , exhibiting rapidly interconverting helical conformers for chiroptical sensing of amines, amino acids, alcohols, and terpenes at micromolar concentrations in water is evaluated. The formation of 1 : 1 host–guest complexes results in spontaneous induction of circular dichroism signals that can be used for accurate determination of the absolute configuration and enantiomeric composition of the analyte based on a simple mix-and-measure protocol. 

Naphthalene diimides (NDIs) are shown to arrange spontaneously co-facially with cucurbit[8]uril (CB[8]) in an aqueous environment through purely non-covalent interactions. The resultant 2 : 2 supramolecular complex of NDI and CB[8] is highly fluorescent (>30 times more than the constituent NDIs) due to the formation of NDI–NDI excimers within the supramolecular complex. 

We developed an epigenetically active, cooperative DNA binding transcription factor platform assisted by cucurbit[7]uril (CB7) host–guest modules. This new type of molecule termed ePIP–HoGu not only mimics the operation of transcription factors as a pair but also recruits the epigenetic modifier to a particular DNA locus.