ABSTRACT Ligand‐induced structural transformation has been developed as an effective strategy to manipulate the geometric/electronic structures, elemental compositions, and physicochemical properties of atomically precise silver clusters. In this work, we have demonstrated how a small structural change in the configuration of a bowl‐like antimonotungstate ( {Sb 3 W 30 }‐3 ) ligand can make a big difference in the synthesis of polyoxometalate (POM)‐encapsulated Ag clusters (Ag n @POM). The new bowl‐like {Sb 3 W 30 }‐3 can successfully induce the formation of a {Ag 7 } cluster, {Ag 7 (Sb 3 W 30 )} . Interestingly, the {Ag 7 (Sb 3 W 30 )} cluster, which can generate exposed Ag sites upon removal of three labile CH 3 CN ligands, serves as a common building block for constructing three new types of Ag n @POM derivatives, namely polymeric {Ag 7 (Sb 3 W 30 )} n , {Ag 15 (Sb 3 W 30 ) 2 } , and {Ag 23 (Sb 3 W 30 ) 2 } , via either inter‐cluster assembly or intra‐cluster kernel growth processes. In addition, photocatalytic H 2 evolution studies reveal the importance of accessibility to highly exposed Ag active sites and their synergistic cooperation with the redox‐active bowl‐like {Sb 3 W 30 }‐3 ligand. This study establishes a strategic platform for the rational design and structural evolution of Ag n @POM clusters, demonstrating how subtle modulation of all‐inorganic POM ligands influences their geometric and catalytic properties at the atomic level.

Herein, an undergraduate experiment design is reported to probe chemical bond energy using an instructional mass spectrometer. The experimental procedure involved measuring the dissociation energy of chemical bonds by precisely modulating the electron energy during ionization. This energy was determined by correcting the threshold appearance energy of the resulting fragment ions. Acetonitrile, nitrogen, and oxygen were used as standard substances and target samples to calibrate the electron energy within the ion source and validate the proposed method. This practical laboratory exercise, conducted for chemistry undergraduates, enabled students to master the entire workflow of electron ionization-mass spectrometry (EI-MS), including fundamental principles, instrument tuning, spectral interpretation, and the determination of chemical bond energy. Teaching evaluations indicated that the experiment significantly enhanced student interest, practical skills, and their understanding of the relation between chemical bond stability and instrumental parameters. This study offers a replicable model for integrating modern analytical techniques with basic chemical knowledge into undergraduate laboratory curricula.

The controlled assembly of giant polyoxometalates (POMs) remains a significant challenge in inorganic chemistry. Herein, we demonstrate that rare-earth ions can direct distinct structural outcomes in nickel-substituted tungstate systems. Hydrothermal reaction of the flexible precursor [B-α-SbW9O33] with KH2PO4, Er2O3, and NiCl2 yielded a giant all-inorganic cluster {W88Ni39} (1), adopting an unprecedented "Teddy-Bear"-like architecture. Under identical conditions, omission of Er2O3 (or replacement with Dy2O3) afforded the smaller cluster {W55Ni17} (2), corresponding to the "head" of the "Teddy-Bear". Notably, Dy2O3 improves the crystallization yield of {W55Ni17} relative to the rare-earth-free reaction. Remarkably, replacing Er2O3 with Gd2O3 afforded a giant tetramer {W140Gd10Ni48} (3), whose monomer is analogous to the [W33Ni21] "Teddy-Bear body" motif in {W88Ni39}. These clusters rank among the largest discrete tungsten-based POM assemblies known. Importantly, the crystallization of {W88Ni39} and {W140Gd10Ni48} enables an efficient organic-free separation of the rare-earth oxides Er2O3 and Gd2O3 with a separation factor of 360.37, revealing a new strategy based on structure-directed hierarchical assembly for selective crystallization in rare-earth-mediated POM systems.

Correction for 'Highly stable bidentate thiol-protected Ag5Cu4 nanoclusters: a stable catalyst for enhanced Knoevenagel condensation' by Yan Nong et al., Chem. Commun., 2025, 61, 6933-6936, https://doi.org/10.1039/D5CC00825E.

Reported herein is an introduction to an instructional mass spectrometer, which consists of six parts, an injection system, ion source, pulse accelerator, mass analyzer, detector, and vacuum system, for undergraduate-designed chemical analysis experiments. In the experiment, students must manually assemble the instructional mass spectrometer from the building blocks and adjust parameters to deepen their understanding of the principles and structure of mass spectrometry. Then, using a homemade instructional mass spectrometer, they measure the sample to obtain its corresponding mass spectrum and deduce the chemical composition according to the molecular and fragment ions by analyzing the isotopes and relative abundances. We conducted practical instruction for undergraduate students majoring in chemistry. Students had significant gains in using the mass spectrometer, analyzing mass spectra, and assembling the instrument, showing high enthusiasm for the original experiments.

The assembly of metal ions with peptides to create protein mimics has attracted considerable attention in synthetic chemistry. Despite progress in designing metal-peptide assemblies (MPAs), challenges remain in replicating the complexity of natural proteins, particularly in regulating subunit conformations and constructing large cavities. Herein, we report the successful construction of a giant chiral metalpeptide cage, D/L-Ni45L30, achieved through the deprotonation-driven self-assembly of Gly-D/L-Leu dipeptide-derived ligands and Ni2+ ions. The cage is composed of 15 [Ni3L2] subunits arranged with fivefold symmetry, forming a composite polyhedron that resembles a pentagonal prism with five quadrangular pyramids. Structural analysis reveals that the peptide ligands display conformational diversity, with distinct V-shaped [Ni3L2] subunits coexisting within the structure. The adaptability of these subunits is driven by hydrophobic interactions and steric hindrance, an exceptional feature in artificial MPAs. Through chiral transfer from the peptide, the metal-peptide cage acquires strong chiroptical properties, manifesting as circular dichroism signals that extend from the visible into the near-infrared regime.

The pervasive presence of toroidal architectures across scales, from molecular assemblies to cosmic formations, reveals a universal design principle that integrates aesthetic symmetry with functional topology in nature. Yet, constructing such hierarchical toroidal organization at the nanoscale, particularly for metal nanoclusters, remains an unmet challenge. We present an unprecedented wheel-shaped silver nanocluster, [(V6O19⊂V22O66)@Ag96(tBuPhC≡C)56(SO4)2(DMF)12]6+ (Ag96), encapsulating an unparalleled hierarchical toroidal [V6O19⊂V22O66]30- polyoxovanadate (POV). The hierarchical toroidal [V6O19⊂V22O66]30- mirrors the core-shell geometry of Hoag's Object, a rare ring galaxy, with a Lindqvist-type [V6O19]8- core enclosed by a macrocyclic [V22O66]22- shell. This work constitutes a unique astronomical morphology in coinage metal nanoclusters, uncovering the universal principles of hierarchical self-assembly at the nanoscale. Leveraging the flexibility of POVs, we further isolated a bowl-shaped [(SO4@V15O42)@Ag46(tBuPhC≡C)31(DMF)2]4+ (Ag46), encapsulating an open-cage [SO4@V15O42]11- template by regulating the stoichiometric ratio. Due to their distinct structural configurations, these nanoclusters exhibit markedly different photothermal conversion performance when exposed to visible or near-infrared (NIR) lasers. This breakthrough positions POVs as versatile templates for engineering complex metal nanoclusters, opening new frontiers in materials science and nanotechnology.

Innovation in synthesis methodologies is crucial for advancing the discovery of new materials. This work reports the electrosynthesis of a [Au13(4-tBuPhC≡C)2(Dppe)5]Cl3 nanocluster (Au13 NC) protected by alkynyl and phosphine ligands. From simple precursor, HAuCl4 and ligands, the whole synthesis is driven by a constant potential in single electrolytic cell. X-ray crystallography determines its total structure. Control experiments, cyclic voltammetry, Proton Nuclear Magnetic Resonance (1H NMR), gas chromatography, and other characterizations demonstrate that a critical tetranuclear Au(I) complex defines the electrochemical redox behavior of the reaction solution. The critical role of a base (e.g., triethylamine) is to suppress the hydrogen evolution reaction at the cathode, paving the way for the reduction of Au ions. To resolve the problem of over-reduction and deposition of Au on the cathode, pulsed electrolysis, which is specific to electrosynthesis is employed. It significantly improves the reaction rate and the isolated yield of Au13. To extend the application scope, another four NCs protected by different ligands, [Au13(4-FPhC≡C)2(Dppe)5]Cl3, [Au8(2-CF3PhC≡C)2(Dppp)4](PF6)2, [Au11(Dppp)5]Cl3, and [Au8(SC2H4Ph)2(Dppp)4]Cl2 are synthesized electrochemically, demonstrating the versatility of the strategy.

Reported herein is a study of intercluster exchanges of ligands and/or metals between [(AuAg)44(SR)30]4- nanoclusters via a combination of electrospray ionization mass spectrometry, X-ray crystallography, and UV-vis spectroscopy. The results revealed that ligand exchange reactions are instantaneous, giving rise to the standard Gaussian distribution indicative of a random exchange or substitution process. In sharp contrast, metal exchange reactions are slow (hours to days), resulting in fractal-like patterns. The intercluster Au-Ag exchange occurs in the innermost icosahedral core of the cluster. These reactions, when performed with a permeable membrane separating the two reactants, provided strong evidence that both exchanges require bimolecular collisions resembling conventional SN2-type reactions between two superatomic clusters. This notion was further corroborated by the unexpected observation of "half" Au and "half" Ag peaks in the mass spectra, which may be taken as circumstantial evidence for the formation of a transient dimer [(AuAg)44(SR)30]28- upon intercluster collisions in solution. Finally, the effects of experimental conditions, such as solvent and temperature, were also investigated.

The bidentate thiol-protected Ag5Cu4 nanocluster exhibits exceptional stability, achieving 91% yield in the Knoevenagel condensation of benzaldehyde and malononitrile (24 h). Upon carbon black immobilization, the yield rises to 97%, demonstrating enhanced catalytic synergy and robust heterogeneous catalysis.

The first copper-hydride nanocluster featuring eight free valence electrons has been successfully isolated and characterized spectroscopically. The structure of the nanocluster, represented by the chemical formula [Cu47(PhSe)15(PPh3)5(CF3COO)12H12] (referred to as Cu47H12, where PPh3 denotes triphenylphosphine), has been precisely determined through single crystal X-ray diffraction analysis. Several distinguishing features differentiate the Cu47H12 clusters from previously reported examples. In terms of composition, these clusters represent a rare instance of high-nuclearity Cu nanoclusters containing hydride and stabilized by selenolate ligands. From an electronic standpoint, the stabilization of the nanocluster is achieved through its eight free valence electrons, marking it as the first copper-hydride cluster with this configuration. The alloying chemistry of the nanocluster also introduces unexpected findings in the field. The incorporation of silver atoms leads to the formation of [(CuAg)47(PhSe)18(PPh3)6(CF3COO)12H6]3+ clusters, which exhibit significant structural differences from the parent cluster. Both the homo and alloy clusters display dual-emission properties at 298 K, with the clusters additionally showcasing triple or even quadruple emission at 77 K. This work is anticipated to stimulate research interest in hydride-containing metal nanoclusters, focusing not only on compositional tailoring and structural engineering, but also on electronic structure details and potential applications.

Conventional coinage metal nanocluster (NC) synthesis usually requires premixing reagents in bulk solution until thermodynamic equilibrium, inherently precluding on-demand kinetic manipulation. This study reports the first electrosynthesis of a bimetallic NC with atomic precision, demonstrating real-time kinetic control via electrical signal modulations. Key findings reveal that (1) pulsed potential suppresses cathodic deposition more effectively than constant potential; (2) reaction kinetics exhibit a volcano-shaped dependence on pulse duration, with optimal performance at ∼ 10 s; (3) reactions can be instantaneously switched on or off by applying or removing the potential; and (4) reaction rates are precisely tunable via pulse off-time adjustment. This work establishes an electrical signal-modulated strategy for real-time reaction control, presenting a viable strategy for the programmable and controllable synthesis of metal NCs.

Metal nanoclusters (MNCs) feature robust metallic cores and flexible ligands, granting them the potential to mimic natural enzymes. However, their enzymatic activities remain largely underdeveloped. Inspired by natural small molecule coenzymes, this work utilizes biological antioxidants as coenzymes to achieve specific regulation of the peroxidase activity of Ag6 clusters (NCs). This high specificity arises from the weak interactions (hydrogen bonding, it-it stacking) between the antioxidants and the MNCs ligands, which form enzyme pockets that enhance H2O2 adsorption and facilitate its own reduction. Furthermore, based on the specific interactions between antioxidants and Ag6 NCs, we have developed a dual-channel colorimetric array sensing platform for detecting a range of biological antioxidants, including ascorbic acid, melatonin, uric acid, dopamine, and glutathione. Combined with linear discriminant analysis, this platform accurately identifies various concentrations of single and mixed biological antioxidants, as well as human serum samples. This study not only introduces a new mechanism for clusters in enzyme mimicry but also proposes a novel method for designing highly selective MNCs catalysts capable of simultaneous detection and analysis of multiple target components.

Atomically precise metal nanoclusters (MNCs) with flexible peripheral ligands provide selective channels and unique electronic structures to the rigid metal core, showing great application potential in many fields such as biomimetic nanozymes. In this study, we developed cost-effective, low-toxicity, and water-soluble MNC based self-cascade antioxidants for enhanced reactive oxygen species clearance. Compared to Ag nanoparticles, the Ag9 NCs with a monovalent Ag core coordinated by nonmetallic S and O show superior superoxide dismutase-like (inhibition 86.7%) and catalase-like (K m = 20.37 mM, V max = 3.13 x 10-3 mM s-1) activities. Interestingly, the -COOH groups on the ligands endow Ag9 NCs with a -42.5 mV negative surface charge, enhancing the targeting to inflammatory cells. Additionally, Ag9 NCs' remarkable therapeutic effects have been confirmed in cell cultures and an inflammatory bowel disease (IBD) model. Thus, this study proposes a novel cluster-based nanozyme that utilizes ligands for targeting and monovalent metal cores for catalysis, demonstrating significant therapeutic potential for IBD treatment.

Two structurally new Lindqvist hexaniobate-templated silver thiolate clusters, [Nb6O19@Ag45(iPrS)23(CH3COO)14] (Ag45) and (H3O)4[Nb6O19@Ag41KS2.5O2(H2O)7.5(iPrS)24(CH3COO)5] (Ag41), were synthesized using a facile one-pot solvothermal approach. Single crystal X-ray diffraction analyses revealed the presence of a classical Lindqvist-type [Nb6O19]8- anion template, with iPrS- and CH3COO- surface-protecting ligands in both silver clusters, which can further form two-dimensional Ag45 assembly and one-dimensional Ag41 chain packing structures. Both Ag45 and Ag41 clusters exhibited intriguing photothermal conversion properties and temperature-dependent emission behavior. Two structurally new hexaniobate-templated silver thiolate clusters are prepared using a solvothermal approach, which can form a 2D Ag45 and 1D Ag41 packing structures with intriguing photothermal conversion and temperature-dependent emission properties.

In recent years, luminescent materials have received a great deal of attention due to their wide range of applications. However, exploring a simple solution to overcome the fluorescence quenching resulting from the aggregation of conventional organic fluorophores remains a valuable area of investigation. In this study, we successfully constructed two metallo-cages, namely, SA and SB, through coordination-driven self-assemblies of the triphenylamine (TPA)-based donor L with different diplatinum(II) acceptors LA and LB, respectively. These metallo-cages take advantage of their steric nature and curved conformation to more effectively limit the free rotation of the benzene ring and hinder π-π stacking in the solid state, which successfully inhibited fluorescence quenching and realizing highly efficient luminescent properties. Therefore, this work offers a new design strategy for preparing materials with excellent luminescent properties.

Cluster-assembled nanowires provide a unique strategy for the preparation of high-performance nanostructures. However, existing preparations are limited by complex processes and harsh reaction conditions. Here, Ag+ ions were utilized as a novel structure-directing agent to generate the self-assembly of Pt clusters to form ultrafine nanowires with a diameter of less than 5 nm. Electrospray ionization mass spectrometry (ESI-MS) and extended X-ray absorption fine structure (EXAFS) characterizations demonstrated that every Ag+ bridged two [Pt-3(CO)(3)(mu(2)-CO)(3)](n)(2-) clusters through coordination and formed a sandwich-like structure of [Pt-3(CO)(3)(mu(2)-CO)(3)](n)Ag[Pt-3(CO)(3)(mu(2)-CO)(3)](m)(3-). As a result, multiple sandwich-like structures of [Pt-3(CO)(3)(mu(2)-CO)(3)](n)Ag[Pt-3(CO)(3)(mu(2)-CO)(3)](m)(3-) were established by Ag+ to form Pt nanowire superstructures {[Pt-3(CO)(6)](n)Ag[Pt-3(CO)(6)](m)Ag[Pt-3(CO)(6)](x}infinity) (abbreviated as Ag-Pt NWS). Our results demonstrate that the Pt nanowire superstructures showed promising cocatalytic performance for photocatalytic H-2 production with the involvement of Ag+, which promises a desirable way to develop advanced functional nanomaterials.

Hydrogen-bonded assembly of multiple components into well-defined icosahedral capsules akin to virus capsids has been elusive. In parallel, constructing robust zeolitic-like cluster-based supramolecular frameworks (CSFs) without any coordination covalent bonding linkages remains challenging. Herein, we report a cluster-based pseudoicosahedral H-bonded capsule Cu60, which is buckled by the self-organization of judiciously designed constituent copper clusters and anions. The spontaneous formation of the icosahedron in the solid state takes advantage of 48 charge-assisted CHF hydrogen bonds between cationic clusters and anions (PF6-), and is highly sensitive to the surface protective ligands on the clusters with minor structural modification inhibiting its formation. Most excitingly, an extended three-periodic robust zeolitic-like CSF, is constructed by edge-sharing the resultant icosahedrons. The perpendicular channels of the CSF feature unusual 3D orthogonal double-helical patterns. The CSF material not only keeps its single-crystal character in the desolvated phase, but also exhibits excellent chemical and thermal stabilities as well as long-lived phosphorescence emission. H-bonded assembly of multiple components into well-defined icosahedral capsules has been elusive, and constructing stable sophisticated cluster-based supramolecular frameworks without coordinative bonding linkages remains challenging. Here, the authors report a cluster-based icosahedral H-bonded capsule Cu60 and its self-propagation into a 3D robust zeolitic-like supramolecular framework.

Coinage-metal clusters with excellent luminescence properties have attracted considerable interest due to their intriguing structures and potential applications. However, achieving strong near-infrared (NIR) luminescence in these clusters is highly challenging. Here, we have successfully synthesized the first LnIII/CuI bimetallic clusters, formulated as [LnCu54O6Cl3(2-MeO-PhC≡C)36] (ClO4)6 (Ln = Yb for YbCu54, Er for ErCu54, and Gd for GdCu54). Single crystal X-ray diffraction showed that the LnCu54 clusters have a three-layered core-shell structure, consisting of (LnO6)@Cu18Cl3@Cu36 units protected by 36 2-MeO-PhC≡C- ligands. Notably, the YbCu54 cluster exhibits significant NIR-II luminescence at 986 nm with the solid quantum efficiency of 33.3%, the highest among Cu clusters with NIR-II emission. This work not only reports the first category of LnIII/CuI clusters but also presents a method to enhance NIR luminescence in coinage-metal clusters through the incorporation of LnIII ions.

The exploration of artificial metal-peptide assemblies (MPAs) is one of the most exciting fields because of their great potential for simulating the dynamics and functionality of natural proteins. However, unfavorable enthalpy changes make forming discrete complexes with large and adaptable cavities from flexible peptide ligands challenging. Here, we present a strategy integrating metal-cluster building blocks and peptides to create chiral metal-peptide assemblies and get a family of enantiopure [R-/S-Ni3L2]n (n = 2, 3, 6) MPAs, including the R-/S-Ni6L4 capsule, the S-Ni9L6 trigonal prism, and the R-/S-Ni18L12 octahedron cage. X-ray crystallography shows MPA formation reactions are highly solvent-condition-dependent, resulting in significant changes in ligand conformation and discrete cavity sizes. Moreover, we demonstrate that a structure transformation from Ni18L12 to Ni9L6 in the presence of benzopyrone molecules depends on the peptide conformational selection in crystallization. This work reveals that a metal-cluster building block approach enables facile bottom-up construction of artificial metal-peptide assemblies. The use of metal clusters to construct artificial protein-mimic structures with adaptable cavities has potential for simulating the dynamics and functionality of natural proteins. Here, the authors develop a family of chiral metal-peptide assemblies using {Ni3} clusters and flexible peptides, resulting in structures such as octahedral cages, trigonal prisms, and capsules.