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A porous three-component hydrogen bonded framework, 1⋅biphen⋅TP, was prepared from a tetra-amidinium component (14+) and two different dianions, benzene-1,4-dicarboxylate (terephthalate, TP2−) and biphenyl-4,4′-dicarboxylate (biphen2−). Interestingly, when the framework was prepared in ethanol/water, 1⋅biphen⋅TP forms even when an excess of either dicarboxylate is present. However, when only water is used as solvent, only two-component frameworks are formed. [ABSTRACT FROM AUTHOR]

This document titled "(Self) Assembled news: recent highlights from the supramolecular chemistry literature (quarter 3, 2024)" provides a summary of recent advancements in the field of supramolecular chemistry. The first highlight discusses the development of a supramolecular system that functions as a molecular ion pump, converting light energy into work and pumping KCl across a hydrophobic barrier against the concentration gradient. The second highlight focuses on the development of a supramolecular gel that can trap, protect, and release sensitive proteins without the need for additional excipients and cold-chain management. The third highlight explores the use of classical supramolecular binding events to improve the reliability of decoding synthetic digital polymers. The document also briefly mentions other advancements in the field, such as the development of multiply-switchable foldamers and the use of supramolecular guest binding in electrocatalytic reactions. [Extracted from the article]

This document provides a summary of recent highlights in the field of supramolecular chemistry. The first highlight discusses the use of foldamers to transport single-stranded DNA across lipid membranes. Two different foldamers were tested and found to bind to DNA with high affinity, with one foldamer preferentially binding to single-stranded DNA and the other preferentially binding to double-stranded DNA. Both foldamers were able to effectively transport single-stranded DNA into human cells. The second highlight describes a study that used a relatively inexpensive liquid handling platform to automate the discovery of imine cages. The study screened 366 precursor combinations and identified 54 combinations that successfully formed a single soluble cage topology. Computational modeling was used to predict the most likely cage types and determine their porosity. The third highlight discusses the use of highly polarized C-H hydrogen bonds as anion recognition motifs. A recent study demonstrated that adding nitro groups to phenyl rings of resorcin[4]arenes enhanced their halide anion recognition properties, even in aqueous media. The fourth highlight presents a mechanochemical approach to the synthesis of mixed-ligand cages, which can be achieved through solvent-free grinding. This approach allows for faster and more efficient ligand exchange compared to traditional solution-based methods. The fifth highlight introduces the use of chemically sensitive field effect transistor (ChemFET) technology to study anion binding. By drop-casting a hydrophobic anion receptor blended with a polymer onto [Extracted from the article]

This experiment prepares a large (M[subscript r]: 1821 g mol[superscript -1]) triple helicate complex quickly in one pot from inexpensive starting materials. The protocol illustrates the power of self-assembly in a simple manner that is suitable for second-year general chemistry students using reversible imine bond and metal-ligand bond formation. Plastic molecular models and [superscript 1]H NMR spectroscopy are used to elucidate the structure of the self-assembled product.

A simple dihydroxy isoquinolinium molecule (3+) was prepared by a modification of a literature procedure. Interestingly, during optimisation of the synthesis a small amount of the natural product pseudopalmatine was isolated, and characterised for the first time by X‐ray crystallography. Compound 3+ contains a catechol motif and positive charge on the same scaffold and was found to be a potent anion receptor, binding sulfate strongly in 8 : 2 d6‐acetone:D2O and 7 : 3 d6‐acetone:D2O (Ka>104 and 2,100 M−1, respectively). Unsurprisingly, chloride binding was much weaker, even in the less polar solvent mixture 9 : 1 d6‐acetone:D2O. The sulfate binding is remarkably strong for such a simple molecule, however anion binding studies were complicated by the tendency of the molecule to react with BPh4− or BF4− species during anion metathesis reactions. This gave two unusual zwitterions containing tetrahedral boronate centres, which were both characterised by X‐ray crystallography. [ABSTRACT FROM AUTHOR]

Hydrogen-bonded frameworks were prepared from a tetra-amidinium component and three-dimensional cubane and bicyclopentane dicarboxylate linkers. Despite the incorporation of aliphatic components, the frameworks demonstrate strong and reversible uptake of water vapour, with one of the frameworks showing water uptake at very low relative humidity. [ABSTRACT FROM AUTHOR]

In this work, we studied the encapsulation of a range of proteins in a hydrogen-bonded organic framework (HOF) comprised of a tetraamidinium cation and diazobenzene-based dicarboxylate anion. We explore the use of external stimuli: light and temperature to modulate HOF crystal growth and size. In particular, we found photo-isomerisation can be used to control the concentration of the trans-azobenzene building block that contributes to HOF formation. When HOF growth was slowed sufficiently, deformation of the crystals and ultimately multicrystal aggregates were observed in the presence of some proteins. We propose that the extent of crystal deformation, consistent with better protein association, may be governed by differences in the type and strength of interactions between proteins and the surface of the growing HOF crystals. [ABSTRACT FROM AUTHOR]

This editorial discusses a recent paper published in the journal Supramolecular Chemistry that examines a model for fitting host-guest binding data. The paper received mixed reviews from anonymous reviewers, but after addressing their concerns and making revisions, it was accepted for publication. The authors acknowledge the possibility that the variation in binding affinity observed at different concentrations could be due to the influence of activity coefficients, particularly in the case of certain host molecules. They suggest that further research is needed to explore these possibilities and provide a larger dataset for analysis. The authors also conducted experiments on binding equilibria using different reactants and hosts, and while the results showed a decrease in binding affinity at lower reactant concentrations, the overall conclusions remained unchanged. The authors believe that their approach offers a new perspective on solution thermodynamics in biology, but acknowledge the need for further validation and critical examination. [Extracted from the article]

This article provides a review of recent highlights in the field of supramolecular chemistry. It discusses several key findings, including the development of a neutral urea cryptand that can bind sulfate in water, the observation of photo-triggered disassembly of a supramolecular polymer using atomic force microscopy, the creation of circularly polarized luminescence materials that can emit both left-handed and right-handed luminescence, the discovery of a quadruple amide receptor that selectively binds multivalent anions, the formation of hydrogels at physiological pH using amino-acid appended perylene bisimides, and the study of arylaminopyrazoles as a new class of small molecule photo-switch. These findings contribute to the understanding and potential applications of supramolecular chemistry. [Extracted from the article]

This article provides a summary of recent highlights in the field of supramolecular chemistry. It discusses the importance of ion pairing, even in water, and how it can affect the measurement of association constants. The article also highlights a sensor library that can accurately identify nucleotides, which is challenging due to their similar chemical structures. Additionally, the article explores the use of hydrogen bonding halides to separate noble gases and the synthesis of porous organometallic frameworks. It also mentions a study on the structure of supramolecular cages using DOSY NMR and the assembly of low symmetry metal-organic cages. Lastly, the article discusses the association of oligourea foldamers with surfactants. [Extracted from the article]

A new alkyne‐based hydrocarbon cage was synthesized in high overall yield using alkyne‐alkyne coupling in the cage forming step. The cage is porous and displays a moderately high BET surface area (546 m2 g−1). The cage loses crystallinity on activation and thus is porous in its amorphous form, while very similar cages have been either non‐porous, or retained crystallinity on activation. Reaction of the cage with Co2(CO)8 results in exhaustive metalation of its 12 alkyne groups to give the Co24(CO)72 adduct of the cage in good yield. [ABSTRACT FROM AUTHOR]

The assembly of hydrogen bonded cages using amidinium...carboxylate hydrogen bonding interactions was investigated. A new tris-amidinium hydrogen bond donor tecton based on a tetraphenylmethane scaffold was prepared and its selfassembly with the terephthalate anion studied, and a new tricarboxylate hydrogen bond acceptor tecton was synthesised and its assembly with the 1,3-benzenebis(amidinium) hydrogen bond donor explored. In both cases, molecular modelling indicated that the formation of the cages was geometrically feasible and 1H NMR spectroscopic evidence was consistent with interactions between the components in competitive d6-DMSO solvent mixtures. DOSY NMR spectroscopy of both systems indicated that both components diffuse at the same rate as each other, and diffusion coefficients were consistent with cage formation, and with the formation of assemblies significantly larger than the individual components. An X-ray crystal structure showed that one of the assemblies did not have the desired cage structure in the solid state. [ABSTRACT FROM AUTHOR]