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Since the discovery of X-rays by Roentgen in 1895, its use has been ubiquitous, from medical and environmental applications to materials sciences 1 – 5 . X-ray characterization requires a large number of atoms and reducing the material quantity is a long-standing goal. Here we show that X-rays can be used to characterize the elemental and chemical state of just one atom. Using a specialized tip as a detector, X-ray-excited currents generated from an iron and a terbium atom coordinated to organic ligands are detected. The fingerprints of a single atom, the L 2,3 and M 4,5 absorption edge signals for iron and terbium, respectively, are clearly observed in the X-ray absorption spectra. The chemical states of these atoms are characterized by means of near-edge X-ray absorption signals, in which X-ray-excited resonance tunnelling (X-ERT) is dominant for the iron atom. The X-ray signal can be sensed only when the tip is located directly above the atom in extreme proximity, which confirms atomically localized detection in the tunnelling regime. Our work connects synchrotron X-rays with a quantum tunnelling process and opens future X-rays experiments for simultaneous characterizations of elemental and chemical properties of materials at the ultimate single-atom limit. Using a specialized tip as a detector, the fingerprints of a single atom of iron and terbium are observed in synchrotron X-ray absorption spectra, allowing elemental and chemical characterization one atom at a time.

HighlightsThe N/S co-doped lignin-derived porous carbon (NSLPCs) with ultra-high heteroatom doping was prepared through a novel supramolecule-mediated pyrolysis strategy.Covalently bonded graphitic carbon/amorphous carbon intermediates induce the formation of high heteroatom doping.The high heteroatom doping of NSLPC could provide abundant defective active sites for the adsorption of K+.Amorphous carbons are promising anodes for high-rate potassium-ion batteries. Most low-temperature annealed amorphous carbons display unsatisfactory capacities. Heteroatom-induced defect engineering of amorphous carbons could enhance their reversible capacities. Nevertheless, most lignocellulose biomasses lack heteroatoms, making it a challenge to design highly heteroatom-doped carbons (> 10 at%). Herein, we report a new preparation strategy for amorphous carbon anodes. Nitrogen/sulfur co-doped lignin-derived porous carbons (NSLPC) with ultra-high nitrogen doping levels (21.6 at% of N and 0.8 at% of S) from renewable lignin biomacromolecule precursors were prepared through a supramolecule-mediated pyrolysis strategy. This supermolecule/lignin composite decomposes forming a covalently bonded graphitic carbon/amorphous carbon intermediate product, which induces the formation of high heteroatom doping in the obtained NSLPC. This unique pyrolysis chemistry and high heteroatom doping of NSLPC enable abundant defective active sites for the adsorption of K+ and improved kinetics. The NSLPC anode delivered a high reversible capacity of 419 mAh g‒1 and superior cycling stability (capacity retention of 96.6% at 1 A g‒1 for 1000 cycles). Potassium-ion hybrid capacitors assembled by NSLPC anode exhibited excellent cycling stability (91% capacity retention for 2000 cycles) and a high energy density of 71 Wh kg–1 at a power density of 92 W kg–1.

The translational diffusivity of covalent open‐[60]fullerene dimers in an organic solvent was found to be well describable by a prolate ellipsoid model while a monomeric open‐[60]fullerene behaves like a sphere model. The water association dynamics were examined for two open‐[60]fullerene dimers, showing a higher water affinity for the sp3‐linked dimer relative to sp2‐linked dimer owing to an effective orbital–orbital overlap identified by π(fullerene)→σ*(H2O) interactions as suggested by theoretical calculations. A prolate ellipsoid model could accurately estimate the size of covalent open‐[60]fullerene dimers from translational diffusion coefficients measured in solution. The sp3‐linked dimer showed a higher water affinity than the sp2‐linked dimer owing to stronger π(fullerene)→σ*(H2O) interactions.

The controlled supramolecular alignment of atomically precise metal nanoclusters is a promising method to unlock unprecedented properties and advanced functions beyond those of the individual monomeric nanoclusters. Conventional protocols for the construction of such assemblies require the use of two or more types of ligands for protecting and interconnecting the nanoclusters, respectively. Herein, a strategy is demonstrated for the hierarchical self‐assembly of an alkyne‐protected silver nanocluster into a 3D network in the crystalline lattice based on cooperative silver···acetylene coordination and silver···pyridyl coordination by a bifunctional ligand with a simple design. The bent ligand L produces a Cl@Ag14L12 monomer with a helical conformation resembling that of organic tripodal ligands, which assembles into a 3D network as evident from a single‐crystal X‐ray diffraction analysis. The monomeric and network structures are further characterized using grazing‐incidence small‐angle X‐ray scattering, atomic force microscopy, X‐ray photoelectron spectroscopy, and X‐ray absorption fine structure, in addition to photoluminescence with a microsecond lifetime in the solid state, exhibiting the success of the strategy toward the design of self‐assembled 3D supramolecular arrangements of atomically precise metal nanoclusters using a single, simple ligand. A strategy for the hierarchical self‐assembly of an emissive silver nanocluster into a 3D crystalline lattice via cooperative acetylene bonding in concert with networking silver···pyridyl coordination embodying the hexadentate form is demonstrated.

Chirality in biomolecules is ubiquitous in our world, but oral nanomedicines constructed from chiral peptides are extremely rare, principally because of the immature nanofabrication and inadequate bioavailability of chiral nanostructures. To realize the oral administration of chiral peptides and break through their forbidden zone in intracellular space, a chiral-peptide supramolecular (DPAICP) camouflaging with the membrane from milk-derived extracellular vesicles (ME) was developed herein through an aqueous-based growth method of chiral peptide Au(I) infinite covalent polymer (DPAICP) involving in organothiol D-peptides and Au , and a feasible camouflage technology using ME. DPAICP@ME possessed favorable pharmaceutical properties to remain stable during the gastrointestinal absorption and blood circulation, and showed the satisfactory tumor accumulation through oral medication. Expectedly, oral DPAICP@ME played its predetermined role to restore p53 signaling pathway for cancer therapy in B16F10 homograft malignant melanoma model, LLC Lewis orthotopic transplantation model of lung cancer and patient-derived orthotopic xenograft (PDOX) mice model of colon cancer. Moreover, oral DPAICP@ME augmented the action of immunotherapy by Anti-PD1 through the further T-cell activation. The design of the bionic chiral-peptide supramolecule provides a practicable strategy for the construction of biomimetic chiral peptide-derived nanostructures that can be taken orally, and likely boosts chiral nanomedicine discovery efforts for a wider range of diseases including cancer.

Chiral separation is an important process in the chemical and pharmaceutical industries. From the analytical chemistry perspective, chiral separation is required for assessing the fit-for-purpose and the safety of chemical products. Capillary electrophoresis, in the electrokinetic chromatography mode is an established analytical technique for chiral separations. A water-soluble chiral selector is typically used. This review therefore examines the use of various chiral selectors in electrokinetic chromatography during 2017–2018. The chiral selectors were both low and high (macromolecules) molecular mass molecules as well as molecular aggregates (supramolecules). There were 58 papers found by search in Scopus, indicating continuous and active activity in this research area. The macromolecules were sugar-, amino acid-, and nucleic acid-based polymers. The supramolecules were bile salt micelles. The low molecular mass selectors were mainly ionic liquids and complexes with a central ion. A majority of the papers were on the use or preparation of sugar-based macromolecules, e.g., native or derivatised cyclodextrins. Studies to explain chiral recognition of macromolecular and supramolecular chiral selectors were mainly done by molecular modelling and nuclear magnetic resonance spectroscopy. Demonstrations were predominantly on drug analysis for the separation of racemates.

This paper reviews the most stable conformation of crystalline three-dimensional cyclophane (CP) achieved by self-assembling based on changing the type of aromatic compound or regulating the type and number of bridging groups. [3n]cyclophanes (CPs) were reported to form supramolecular compounds with bind organic, inorganic anions, or neutral molecules selectively. [3n]cyclophanes ([3n]CPs) have stronger donor capability relative to compound [2n]cyclophanes ([2n]CPs), and it is expected to be a new type of electron donor for the progress of fresh electron conductive materials. The synthesis, conformational behavior, and properties of crystalline multi-bridge rings are summarized and discussed.

With the application of the concept of supramolecular chemistry to various fields, a large number of supramolecules have been discovered. The chemical components of traditional Chinese medicine have various sources and unique structures. During the high-temperature boiling process, various active components form supramolecules due to complex interactions. The supramolecular structure in a traditional Chinese medicine decoction can not only be used as a drug carrier to promote the absorption and distribution of medicinal components but may also have biological activities superior to those of single active ingredients or their physical mixtures. By summarizing the relevant research results over recent years, this paper introduces the research progress regarding supramolecules in various decoctions, laying a foundation for further research into supramolecules in traditional Chinese medicine decoctions, and provides a new perspective for revealing the compatibility mechanisms of traditional Chinese medicine, guiding clinical medications, and developing new nanometers materials.

This review focuses on the synthesis, structure, and interactions of metal ions, the detection of some weak interactions using the structure, and the construction of supramolecules of azacalixarenes that have been reported to date. Azacalixarenes are characterized by the presence of shallow or deep cavities, the simultaneous presence of a basic nitrogen atom and an acidic phenolic hydroxyl group, and the ability to introduce various side chains into the cyclic skeleton. These molecules can be given many functions by substituting groups on the benzene ring, modifying phenolic hydroxyl groups, and converting side chains. The author discusses the evidence of azacalixarene utilizing these characteristics.

We demonstrate a rapid and sensitive boron detection method through current amplification mediated by supramolecular interaction. Oxidation peak currents obtained by cyclic voltammetry (CV) measurements of a ferrocene/catechol-functionalized β-cyclodextrin inclusion complex were amplified through an EC’ reaction (where EC’ denotes an electrochemical step followed by a catalytic chemical step). However, the amplified current was decreased by boric acid (the primary form of boron in water) addition at pH 8.6 owing to interactions of boron with the cis-diol structure of dihydroxybenzoic acid-β-cyclodextrin and ferrocene for ester formation. We determined the optimum CyD functionalization sites and measurement conditions and obtained a limit of detection of 0.16 mg B L−1 for ferrocene/3,4-dihydroxybenzoic acid-β-cyclodextrin (Fc/3,4-DHBA-β-CyD). The binding constant (assuming a 1:1 binding model) for the interaction between Fc/3,4-DHBA-β-CyD and boric acid was estimated to be approximately 1500 M−1. Boron concentrations in spiked real samples showed good recoveries and linear calibration curves. The electrochemical response of this system was not significantly affected by the presence of other anions or cations. We also found that an aqueous solution of 3,4-DHBA-β-CyD remained stable for at least 112 days.