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The crystal orientation and the temperature of the substrate are crucial factors that influence clusters deposition and, consequently, the properties of thin films. In this study, the molecular dynamics simulation method was employed to investigate the deposition of Cu55 clusters on Fe(001), Fe(011), and Fe(111) substrates with varying crystal orientations. The incident energies used ranged from 0.1 to 20.0 eV/atom, and the substrates were maintained at temperatures of 300, 500, and 800 K. Analysis of cluster and substrate atom snapshots, along with the physical properties of clusters, revealed how the crystal orientation of Fe substrates affects the morphology and structure of the cluster at different temperatures. Additionally, specific microscopic mechanisms responsible for these effects were identified. The simulation results demonstrate that the crystal orientation of Fe substrate significantly influences the deposition of Cu55 clusters. The structures of the clusters on the three crystal substrates undergo similar changes as the substrate temperature increases, with the Cu55 clusters on the Fe(111) substrate exhibiting the most significant changes in response to the temperature rise. [ABSTRACT FROM AUTHOR]

Improving the atomic utilization of storage sites and developing isotropic transport characteristics become crucial to enhance the performance of potassium‐ion hybrid capacitors (PIHCs), and the disordered strategy and coordination modulation of the electrodes can satisfy the above structure‐activity requirements. Herein, the highly dispersed atomic W‐P clusters are chosen as a platform for the electronic restructuring. Studies and calculations indicate that replacing O in W‐O2/P2 with pyridine N can modulate the electron distribution and electronegativity, and enrich the edge‐dangling bonds of the amorphous clusters (W‐N2/P2), resulting in proper adsorption equilibrium and high affinity for K+ storage. In addition, the clusters have isotropic and bulk‐phase‐indifferent fast ion storage, and in situ protection of carbon nanosheets can provide stable support for ion storage and electron transfer in the clusters. As an anode, the composite (W‐N/P@C) exhibits superior storage properties of K+ (reversible capacity of 181.6 mAh g−1 after 3000 cycles at 5.0 A g−1), with high energy density (163.7 Wh Kg−1) at the high‐power output (3500 W Kg−1) in PIHCs. This work systematically delineates the effects of disordered design and pyridine N‐coordination on energy storage, and provides new research ideas for studying high‐performance PIHCs. [ABSTRACT FROM AUTHOR]

To efficiently desorb H2, pure Mgn (n = 4–8) clusters were chosen for the hydrogen evolution reaction with H2O. At the PBE0/def2‐TZVP level and the PBE0‐D3/def2‐TZVP level, the lowest energy structures of Mgn (n = 4–8) clusters and the most stable structures of Mgn@H2O (n = 4–8) complexes were searched in the local region. The transition state was predicted, and then the hydrogen evolution reaction channel was obtained by using the intrinsic reaction coordinate (IRC) to confirm the transition state. To better analyze the hydrogen reaction mechanism, the character of Mgn@H2O (n = 4–8) complexes and MgnO (n = 4–8) clusters, as well as the atomic charge change trend, were investigated using interaction region indicator function analysis (IRI) and natural population analysis (NPA). The reaction effect of Mg4 cluster and H2O is the worst. The energy barrier does, however, progressively lower as the cluster atom count rises, improving the reaction effect. [ABSTRACT FROM AUTHOR]

Context: Hydrogen has emerged as a promising clean energy carrier, underscoring the imperative need to comprehend its adsorption mechanisms. This study delves into the magnetic and electronic properties of Co-Mo-P clusters, aiming to unveil their catalytic potential in hydrogen production. Employing density functional theory (DFT), we optimized cluster configurations and scrutinized their magnetic behaviors. Our investigation unveiled 16 stable configurations of the ConMoP (n = 1 ~ 5) cluster, predominantly in steric forms. The magnetic attributes were primarily ascribed to the d orbitals of Co metal atoms, with Co3MoP exhibiting exceptional magnetic characteristics. Analysis of density of state diagrams revealed the prevalence of spin-up α-electrons in d orbitals, while spin-down β-electrons attenuated overall magnetic properties. Localized orbital (LOL) analysis highlighted stable covalent bonds within the clusters, affirming their catalytic potential. Orbital delocalization index (ODI) analysis revealed diverse spatial distribution ranges for orbitals across different configurations, suggesting a progressive attenuation of off-domain properties with increasing cluster size. Furthermore, infrared spectroscopy unveiled distinct vibrational peaks in various configurations, indicative of unique infrared activities. These findings contribute to a nuanced theoretical understanding of Co-Mo-P clusters and pave the path for future research aimed at augmenting their catalytic efficiency in hydrogen production. This study underscores the viability of Co-Mo-P clusters as alternatives to conventional Pt catalysts, offering insights into the design of novel materials for sustainable energy applications. Further research is warranted to explore the behavior of the Co-Mo-P system under diverse reaction conditions, fostering advancements in materials and energy science. Methods: In this study, we harnessed the ConMoP (n = 1 ~ 5) cluster as a simulation platform for probing the local structure of the material. Our aim was to scrutinize the magnetism, electronic characteristics influenced by the varying metal atoms within these clusters. A systematic exploration involved incrementing the number of metal atoms and expanding the cluster size to elucidate the corresponding property variations. Density functional theory (DFT) calculations were pivotal to our methodology, employing the B3LYP hybrid functional implemented in the Gaussian 16 software package. The ConMoP (n = 1 ~ 5) cluster underwent optimization calculations and vibrational analysis at the def2-tzvp quantization level, yielding optimized configurations with diverse spin multiplet degrees. To comprehensively characterize and visually represent the stability, electronic features, and catalytic attributes of these configurations, we employed a suite of computational tools. Specifically, quantum chemistry software GaussView and wave function analysis software Multiwfn played integral roles. Through the integrated use of these computational tools, we acquired valuable insights into the magnetism, electronic characteristics of the ConMoP (n = 1 ~ 5) cluster, shedding light on their dependency on distinct metal atoms. [ABSTRACT FROM AUTHOR]

Hydrogen evolution reaction (HER) is a promising route for sustainable hydrogen production. However, its efficiency is limited by kinetic barriers. Herein, we employ density functional theory (DFT) calculations to demonstrate a new strategy of embedding tetrametallic transition metal clusters (3TM 1 -TM 2) into the pores of graphdiyne (GDY) to effectively optimize its HER performance. By screening 900 configurations, 10 prototypes displayed near-ideal hydrogen adsorption free energies. Among them, 3W–Hg@GDY with a ΔG H of −0.00035 eV was identified as the optimal candidate. Analysis of the electronic structure reveals hybridization between the metal d orbitals and GDY p orbitals near the Fermi level, creating partially filled impurity states to promote hydrogen adsorption. Additionally, coordination between the three TM 1 atoms and active TM 2 atom in the cluster enables precise tuning of TM 2 's electron density to achieve a moderate interaction with the adsorbed H, facilitating superior HER catalysis. Our findings showcase a new paradigm of cluster engineering for modulating GDY's reactivity that holds great promise as a universal approach for the design of high-performance GDY-based electrocatalysts beyond HER. Through screening 900 configurations of tetrametallic transition metal clusters embedded in graphdiyne via DFT calculations, we identified 10 prototypes displayed near-ideal hydrogen adsorption free energies. [Display omitted] • Screened 900 GDY-cluster configs; 10 show near-ideal HER adsorption energies. • 3 W–Hg@GDY: ΔG H -0.00035 eV, closest to ideal among prototypes. • Metal d-orbitals, GDY p-orbitals hybridization aids H adsorption. • Precisely tuned electron density on active site via coordination with three atoms enables optimal binding. [ABSTRACT FROM AUTHOR]

Metal individual atoms and few-atom clusters show extraordinary catalytic properties for a variety of organic reactions, however, their implementation in total synthesis of complex organic molecules is still to be determined. Here we show a 11-step linear synthesis of the natural product (±)-Licarin B, where individual Pd atoms (Pd1) catalyze the direct aerobic oxidation of an alcohol to the carboxylic acid (steps 1 and 6), Cu2-7 clusters catalyze carbon-oxygen cross couplings (steps 3 and 8), Pd3-4 clusters catalyze a Sonogashira coupling (step 4) and Pt3-5 clusters catalyze a Markovnikov hydrosylilation of alkynes (step 5), as key reactions during the synthetic route. In addition, the new synthesis of Licarin B showcases an unexpected selective alkene hydrogenation with metal-free NaBH4 and an acid-catalyzed intermolecular carbonyl-olefin metathesis as the last step, to forge a trans-alkene group. These results, together, open new avenues in the use of metal individual atoms and clusters in organic synthesis, and confirm their exceptional catalytic activity in late stages during complex synthetic programmes. Individual metal atoms and few-atom metal clusters have shown promising catalytic activities, however, their exploitation in the total synthesis of complex organic molecules remains underexplored. Here, the authors develop a total synthesis of the bioactive natural product (±)-Licarin B involving key steps catalyzed by soluble individual Pd atoms and Cu/Pd/Pt clusters, achieving an 11-step linear synthesis and overall yield of 13.1%. [ABSTRACT FROM AUTHOR]

Metal individual atoms and few-atom clusters show extraordinary catalytic properties for a variety of organic reactions, however, their implementation in total synthesis of complex organic molecules is still to be determined. Here we show a 11-step linear synthesis of the natural product (±)-Licarin B, where individual Pd atoms (Pd1) catalyze the direct aerobic oxidation of an alcohol to the carboxylic acid (steps 1 and 6), Cu2-7 clusters catalyze carbon-oxygen cross couplings (steps 3 and 8), Pd3-4 clusters catalyze a Sonogashira coupling (step 4) and Pt3-5 clusters catalyze a Markovnikov hydrosylilation of alkynes (step 5), as key reactions during the synthetic route. In addition, the new synthesis of Licarin B showcases an unexpected selective alkene hydrogenation with metal-free NaBH4 and an acid-catalyzed intermolecular carbonyl-olefin metathesis as the last step, to forge a trans-alkene group. These results, together, open new avenues in the use of metal individual atoms and clusters in organic synthesis, and confirm their exceptional catalytic activity in late stages during complex synthetic programmes. Individual metal atoms and few-atom metal clusters have shown promising catalytic activities, however, their exploitation in the total synthesis of complex organic molecules remains underexplored. Here, the authors develop a total synthesis of the bioactive natural product (±)-Licarin B involving key steps catalyzed by soluble individual Pd atoms and Cu/Pd/Pt clusters, achieving an 11-step linear synthesis and overall yield of 13.1%. [ABSTRACT FROM AUTHOR]

Density functional theory (DFT) and coupled cluster theory (CCSD(T)) calculations are performed to investigate the geometric and electronic structures and chemical bonding of a series of Cu-doped zinc oxide clusters: CunZn3O3 (n = 1–4). The structural evolution of CunZn3O3 (n = 1–4) clusters may reveal the aggregation behavior of Cu atoms on the Zn3O3 cluster. The planar seven-membered ring of the CuZn3O3 cluster plays an important role in the structural evolution; that is, the Cu atom, Cu dimer (Cu2) and Cu trimer (Cu3) anchor on the CuZn3O3 cluster. Additionally, it is found that CunZn3O3 clusters become more stable as the Cu content (n) increases. Bader charge analysis points out that with the doping of Cu atoms, the reducibility of Cu aggregation (Cun−1) on the CuZn3O3 cluster increases. Combined with the d-band centers and the surface electrostatic potential (ESP), the reactivity and the possible reaction sites of CunZn3O3 (n = 1–4) clusters are also illustrated. [ABSTRACT FROM AUTHOR]

We examine the many-body expansion (MBE) for alkaline earth metal clusters, Ben, Mgn, Can (n = 4, 5, 6), at the Møller–Plesset second order perturbation theory, coupled-cluster singles and doubles with perturbative triples, multi-reference perturbation theory, and multi-reference configuration interaction levels of theory. The magnitude of each term in the MBE is evaluated for several geometrical configurations. We find that the behavior of the MBE for these clusters depends strongly on the geometrical arrangement and, to a lesser extent, on the level of theory used. Another factor that affects the MBE is the in situ (ground or excited) electronic state of the individual atoms in the cluster. For most geometries, the three-body term is the largest, followed by a steady decrease in absolute energy for subsequent terms. Though these systems exhibit non-negligible multi-reference effects, there was little qualitative difference in the MBE when employing single vs multi-reference methods. Useful insights into the connectivity and stability of these clusters have been drawn from the respective potential energy surfaces and quasi-atomic orbitals for the various dimers, trimers, and tetramers. Through these analyses, we investigate the similarities and differences in the binding energies of different-sized clusters for these metals. [ABSTRACT FROM AUTHOR]

This article investigates the structural stability and hydrogen adsorption performance of Na-decorated heteroborospherene Si 4 B 32 using density functional theory (DFT) methods. DFT calculations demonstrate that six sodium (Na) atoms can successfully and chemically bind to the surface of heteroborospherene Si 4 B 32 , exhibiting a substantial average binding energy of 2.465 eV without clustering. Moreover, the resulting Na 6 Si 4 B 32 structure retains its integrity even after absorbing up to 30 hydrogen (H 2) molecules, with an average adsorption energy of 0.251 eV/H 2. Utilizing DFT analysis, the gravimetric density of Na 6 Si 4 B 32 ·(H 2) 30 can reach 9.143 wt%. Additionally, employing ab initio molecular dynamics (AIMD) simulations, we find that a significant fraction of the H 2 molecules desorb from Na 6 Si 4 B 32 at 300K within 1000 fs. These findings establish the potential of Na-decorated heteroborospherene Si 4 B 32 as a promising candidate for reversible hydrogen storage. The successful binding of Na atoms without clustering and the substantial H 2 adsorption capacity, coupled with the structural stability and facile H 2 desorption observed at moderate temperatures, highlight the viability of this material for practical hydrogen storage applications. [Display omitted] • The Na atoms can bind on the surface of Si 4 B 32 without metal clustering. • The Na 6 Si 4 B 32 cluster can adsorb up to 30H 2 molecules with a hydrogen storage capacity of 9.143 wt%. • H 2 adsorption energy locates in the range from 0.251 to 0.320 eV/H 2. • Dynamics simulation results verify the reversibility of H 2 storage. [ABSTRACT FROM AUTHOR]

A series of new manganese complexes of general formula 32-Mn4Xn , displaying a highly-reproducible [Mn II2 Mn III2 ] cluster core formation, was observed when tetra-p-adamantylcalix[4]arene 3 was used in combination with N,N′-chelating auxiliary ligands, such as bipy (32-Mn4(bipy)2, bipy = 2,2′-bipyridyl) and phen (32-Mn4(phen)2, phen = 1,10-phenanthroline), as well as with DMF/H2O solvent molecules (32-Mn4(dmf)4, 32-Mn4(dmf)2(H2O)2), acting as O-donor coligands, in the crystalline phase. Single-crystal X-ray diffraction revealed that the involvement of auxiliary ligands in coordination with Mn-ions results in the distortion of their coordination sphere and leads to the controlled compression of the {Mn4}-cluster core of complexes. Moreover, the appearance of adamantyl groups at the upper rim of the macrocyclic backbone of 3 influences the crystalline self-assembly of obtained clusters, providing a preferable "side-to-head" orientation of the cluster molecules within the crystal, leading to the observation of relatively higher {Mn4}⋯{Mn4} distances than those revealed for the earlier reported calix[4]arene supported {Mn4} clusters. All 32-Mn4Xn clusters demonstrated ferromagnetic interactions between the metal atoms within the cluster core independent of the nature of the O-donor or N-donor auxiliary ligands. [ABSTRACT FROM AUTHOR]

Atomically defined large metal clusters have applications in new reaction development and preparation of materials with tailored properties. Expanding the synthetic toolbox for reactive high nuclearity metal complexes, we report a new class of Fe clusters, Tp*4W4Fe13S12, displaying a Fe13 core with M−M bonds that has precedent only in main group and late metal chemistry. M13 clusters with closed shell electron configurations can show significant stability and have been classified as superatoms. In contrast, Tp*4W4Fe13S12 displays a large spin ground state of S=13. This compound performs small molecule activations involving the transfer of up to 12 electrons resulting in significant cluster rearrangements. [ABSTRACT FROM AUTHOR]

Atomically defined large metal clusters have applications in new reaction development and preparation of materials with tailored properties. Expanding the synthetic toolbox for reactive high nuclearity metal complexes, we report a new class of Fe clusters, Tp*4W4Fe13S12, displaying a Fe13 core with M−M bonds that has precedent only in main group and late metal chemistry. M13 clusters with closed shell electron configurations can show significant stability and have been classified as superatoms. In contrast, Tp*4W4Fe13S12 displays a large spin ground state of S=13. This compound performs small molecule activations involving the transfer of up to 12 electrons resulting in significant cluster rearrangements. [ABSTRACT FROM AUTHOR]

Monolayer-protected noble metal clusters, also called nanoclusters, can be produced with the atomic precision and in large-scale quantity and are playing an increasingly important role in the field of nanoscience. To outline the origin and the perspectives of this new field, we overview the main results obtained on free metal clusters produced in gas phase including mainly electronic properties, the giant atom concept, the optical properties, briefly the role of the metal atom (alkali, divalent, noble metal) and finally the atomic structure of clusters. We also discuss the limitations of the free clusters. Then, we describe the field of monolayer-protected metal clusters, the main results, the new offered perspectives, the added complexity, and the role of the ligand beyond the superatom concept. [ABSTRACT FROM AUTHOR]

The properties of semiconductor surfaces can be modified by the deposition of metal clusters consisting of a few atoms. The properties of metal clusters and of cluster-modified surfaces depend on the number of atoms forming the clusters. Deposition of clusters with a monodisperse size distribution thus allows tailoring of the surface properties for technical applications. However, it is a challenge to retain the size of the clusters after their deposition due to the tendency of the clusters to agglomerate. The agglomeration can be inhibited by covering the metal cluster modified surface with a thin metal oxide overlayer. In the present work, phosphine-protected Au clusters, Au9(PPh3)8(NO3)3, were deposited onto RF-sputter deposited TiO2 films and subsequently covered with a Cr2O3 film only a few monolayers thick. The samples were then heated to 200 °C to remove the phosphine ligands, which is a lower temperature than that required to remove thiolate ligands from Au clusters. It was found that the Cr2O3 covering layer inhibited cluster agglomeration at an Au cluster coverage of 0.6% of a monolayer. When no protecting Cr2O3 layer was present, the clusters were found to agglomerate to a large degree on the TiO2 surface. [ABSTRACT FROM AUTHOR]

The role of hydrogen atoms as surface ligands on metal nanoclusters is of profound importance but remains difficult to directly study. While hydrogen atoms often appear to be incorporated formally as hydrides, evidence suggests that they donate electrons to the cluster's delocalized superatomic orbitals and may consequently behave as acidic protons that play key roles in synthetic or catalytic mechanisms. Here we directly test this assertion for the prototypical Au9(PPh3)8H2+ nanocluster, formed by addition of a hydride to the well‐characterized Au9(PPh3)83+. Using gas‐phase infrared spectroscopy, we were able to unambiguously isolate Au9(PPh3)8H2+ and Au9(PPh3)8D2+, revealing an Au−H stretching mode at 1528 cm−1 that shifts to 1038 cm−1 upon deuteration. This shift is greater than the maximum expected for a typical harmonic potential, suggesting a potential governing cluster‐H bonding that has some square‐well character consistent with the hydrogen nucleus behaving as a metal atom in the cluster core. Complexing this cluster with very weak bases reveals a redshift of 37 cm−1 in the Au−H vibration, consistent with those typically seen for moderately acidic groups in gas phase molecules and providing an estimate of the acidity of Au9(PPh3)8H2+, at least with regard to its surface reactivity. [ABSTRACT FROM AUTHOR]

The role of hydrogen atoms as surface ligands on metal nanoclusters is of profound importance but remains difficult to directly study. While hydrogen atoms often appear to be incorporated formally as hydrides, evidence suggests that they donate electrons to the cluster's delocalized superatomic orbitals and may consequently behave as acidic protons that play key roles in synthetic or catalytic mechanisms. Here we directly test this assertion for the prototypical Au9(PPh3)8H2+ nanocluster, formed by addition of a hydride to the well‐characterized Au9(PPh3)83+. Using gas‐phase infrared spectroscopy, we were able to unambiguously isolate Au9(PPh3)8H2+ and Au9(PPh3)8D2+, revealing an Au−H stretching mode at 1528 cm−1 that shifts to 1038 cm−1 upon deuteration. This shift is greater than the maximum expected for a typical harmonic potential, suggesting a potential governing cluster‐H bonding that has some square‐well character consistent with the hydrogen nucleus behaving as a metal atom in the cluster core. Complexing this cluster with very weak bases reveals a redshift of 37 cm−1 in the Au−H vibration, consistent with those typically seen for moderately acidic groups in gas phase molecules and providing an estimate of the acidity of Au9(PPh3)8H2+, at least with regard to its surface reactivity. [ABSTRACT FROM AUTHOR]

A crystallographic analysis of two structures, monoclinic Nа8[{Re4(PO)4}(CN)12]⋅18H2O⋅CH3OH (I) and orthorhombic [(C6H5)4P]4 [Ta6I12(CN6)] (II), in which clusters of heavy atoms are significantly rarefied in space, so that their mutual arrangement cannot be explained only in terms of chemical interaction, has been performed. In structure I the crystallographic planes with a high atomic density ("skeletal" planes) are located in the regions with dhkl = 10–5.5 Å and dhkl < 3 Å. The planes in which atomic groups [Re4(PO)4] (playing the role of unified bulk objects) are concentrated are in fact selected in the first region. In the second region, ordering is implemented at the level of individual atoms. A crystallographic analysis showed that the structure basis is determined by the sites of heavy Re cations. A striking fact is that there are 1152 subcells and only 32 Re atoms per unit cell in this structure; i.e., only the fraction of 1/144 provides the basis of structure stability. In structure II "skeletal" planes are also absent in the range of dhkl from ∼7 to ∼4 Å. The planes in the range of large dhkl characterize cluster ordering, whereas the planes in the range of small dhkl characterize ordering of separate atoms. The geometry and local symmetry of the cluster group (Та6 octahedron) dictates the basis of translational symmetry—unified sublattice of sites, most of which are free of these atoms. The considered structures demonstrate the key role of heavy atoms in the formation of translational symmetry—the fundamental difference of the crystalline state from other condensed states. The newly formed structure retains partially local symmetry of cores (templates) of atomic groups, bound by strong chemical interactions, including the interactions between heavy and light atoms. The process of formation of a crystal structure from randomly oriented and randomly located templates—coherence assembly—is implemented according to the laws of dynamics of elastic media, where masses of atoms rather than their chemical characteristics are important. [ABSTRACT FROM AUTHOR]

The adsorption and dissociation of hydrogen molecule on small PdnAgm (n + m ≤ 4) clusters is studied employing density functional theory (DFT) calculations. The lowest energy structures of the PdnAgm clusters are initially presented. Based on the obtained structures, various geometries of H2 adsorption and dissociation with these clusters are examined. The cluster size and composition of the PdnAgm clusters are found to control the nature of the adsorption process. The results suggest that molecular adsorption is more favorable on the Pd atom and mixed clusters, while hydrogen dissociation is more favorable on the Pdn (n = 2–4) clusters. The Pd dimer and trimer are found to be the most reactive clusters for hydrogen adsorption, while single Ag atom is the least reactive one. The natural bond orbital (NBO) population analysis indicates that hydrogen atoms tend to draw electrons from the metal clusters in the dissociative form and donate electrons to the metal clusters in the molecular adsorption form. The density of states (DOS) of the PdnAgm trimers are also presented and discussed. The interaction and stabilities of cluster on the graphene support has also been performed. [ABSTRACT FROM AUTHOR]

Fe−N−C catalysts with single‐atom Fe−N4 configurations are highly needed owing to the high activity for oxygen reduction reaction (ORR). However, the limited intrinsic activity and dissatisfactory durability have significantly restrained the practical application of proton‐exchange membrane fuel cells (PEMFCs). Here, we demonstrate that constructing adjacent metal atomic clusters (ACs) is effective in boosting the ORR performance and stability of Fe−N4 catalysts. The integration of Fe−N4 configurations with highly uniform Co4 ACs on the N‐doped carbon substrate (Co4@/Fe1@NC) is realized through a "pre‐constrained" strategy using Co4 molecular clusters and Fe(acac)3 implanted carbon precursors. The as‐developed Co4@/Fe1@NC catalyst exhibits excellent ORR activity with a half‐wave potential (E1/2) of 0.835 V vs. RHE in acidic media and a high peak power density of 840 mW cm−2 in a H2−O2 fuel cell test. First‐principles calculations further clarify the ORR catalytic mechanism on the identified Fe−N4 that modified with Co4 ACs. This work provides a viable strategy for precisely establishing atomically dispersed polymetallic centers catalysts for efficient energy‐related catalysis. [ABSTRACT FROM AUTHOR]

Fe−N−C catalysts with single‐atom Fe−N4 configurations are highly needed owing to the high activity for oxygen reduction reaction (ORR). However, the limited intrinsic activity and dissatisfactory durability have significantly restrained the practical application of proton‐exchange membrane fuel cells (PEMFCs). Here, we demonstrate that constructing adjacent metal atomic clusters (ACs) is effective in boosting the ORR performance and stability of Fe−N4 catalysts. The integration of Fe−N4 configurations with highly uniform Co4 ACs on the N‐doped carbon substrate (Co4@/Fe1@NC) is realized through a "pre‐constrained" strategy using Co4 molecular clusters and Fe(acac)3 implanted carbon precursors. The as‐developed Co4@/Fe1@NC catalyst exhibits excellent ORR activity with a half‐wave potential (E1/2) of 0.835 V vs. RHE in acidic media and a high peak power density of 840 mW cm−2 in a H2−O2 fuel cell test. First‐principles calculations further clarify the ORR catalytic mechanism on the identified Fe−N4 that modified with Co4 ACs. This work provides a viable strategy for precisely establishing atomically dispersed polymetallic centers catalysts for efficient energy‐related catalysis. [ABSTRACT FROM AUTHOR]

MXenes are promising substrates for supported noble metal electrocatalysts. Yet, it is a significant challenge to modulate the metal–support interaction (MSI) for enhancing catalytic performance. Herein, employing a facile HF etching method, the cation vacancy structures in Ti3C2Tx MXenes are controllably tuned, producing nearly vacancy‐free (Ti3C2Tx‐V0), single Ti atom vacancy (Ti3C2Tx‐VS), or Ti vacancy cluster (Ti3C2Tx‐VC) engineered MXenes. Ruthenium atomic clusters, as a model catalyst, successfully anchor on all MXene substrates. Different from the terminal O/F coordination groups on routine Ti3C2Tx MXene surfaces, the Ti vacancy clusters in Ti3C2Tx‐VC create unique lattice carbon ligand environment toward Ru species, which induces ultra‐strong MSI. As a result, compared to Ti3C2Tx‐V0 and Ti3C2Tx‐VS, the Ti3C2Tx‐VC modulated Ru clusters (Ru@Ti3C2Tx‐VC) exhibit the optimized balance of H2O adsorption/dissociation and OH/H desorption, thereby delivering superior electrocatalytic performance in the alkaline hydrogen evolution reaction (HER). Within the wide range from laboratory‐level (90 mA cm−2) to industrial‐level (1.5 A cm−2) current density, Ru@Ti3C2Tx‐VC outperforms commercial Pt/C in terms of overpotential and mass activity. Moreover, as a universal substrate for noble metal catalysts, Ti3C2Tx‐VC can also anchor Ir/Pt/Rh atomic clusters and enable excellent HER catalytic activity. This work expands the scope of the MSI between MXene and noble metal catalysts. [ABSTRACT FROM AUTHOR]

Atomically precise clusters of group 11 metals (Cu, Ag, and Au) attract considerable attention owing to their remarkable structure and fascinating properties. One of the unique subclasses of these clusters is based on dichalcophosphate ligands of [(RO)2PE2]− type (E = S or Se, and R = alkyl). These ligands successfully stabilise the most diverse Cu, Ag, and Au clusters and superatoms, spanning from simple ones to amazing assemblies featuring unusual structural and bonding patterns. It is noteworthy that such complicated clusters are assembled directly from cheap and simple reagents, metal(I) salts and dichalcophosphate anions. This reaction, when performed in the presence of a hydride or other anion sources, or foreign metal ions, results in hydrido- or anion-templated homo- or heteronuclear structures. In this feature article, we survey the recent advances in this exciting field, highlighting the powerful synthetic capabilities of the system "a metal(I) salt – [(RO)2PX2]− ligands – a templating anion or borohydride" as an inexhaustible platform for the creation of new atomically precise clusters, superatoms, and nanoalloys. [ABSTRACT FROM AUTHOR]

The supporting of pre‐formed soluble metal catalysts on solids is a typical methodology to transform soluble but unrecoverable metal complexes into recoverable and reusable solid catalysts. However, this methodology has been barely implemented for ligand‐less, bare single metal atoms (SMAs) and nanoclusters (NCs) in organic synthesis, despite these ultrasmall species can be formed in‐situ during reaction and be the truly catalytic species. The aim of this review is to explore how to speciate active single metal atoms and clusters during homogeneous catalysis (in solution), without ligands, and to prepare them independently, to be transferred to solid supports and catalyze organic reactions. In many cases, the translation to solids gives single atom catalysts (SACs). Supporting of ultrasmall metal aggregates gives more stable, reusable and, sometimes, chemoselective catalysts for representative organic reactions. [ABSTRACT FROM AUTHOR]

Extremely small metal clusters composed of noble metal atoms (M) have orbitals similar to those of atoms and therefore can be thought of as artificial atoms or superatoms. If these superatoms can be assembled into molecular analogs, it might be possible to create materials with new characteristics and properties that are different from those of existing substances. Therefore, the concept of superatomic molecules has attracted significant attention. The present review focuses on vertex‐shared linear M12n+1 superatomic molecules formed via the sharing of a single metal atom between M13 superatoms having icosahedral cores and summarizes the knowledge obtained to date in this regard. This summary discusses the most suitable ligand combinations for the synthesis of M12n+1 superatomic molecules along with the valence electron numbers, stability, optical absorption characteristics, and luminescence properties of the M12n+1 superatomic molecules fabricated to date. This information is expected to assist in the production of many M12n+1 superatomic molecules with novel structures and physicochemical properties in the future. [ABSTRACT FROM AUTHOR]

The recent advent of cutting-edge experimental techniques allows for a precise synthesis of subnanometer metal clusters composed of just a few atoms, opening new possibilities for subnanometer science. In this work, via first-principles modeling, we show how the decoration of perfect and reduced TiO2 surfaces with Ag5 atomic clusters enables the stabilization of multiple surface polarons. Moreover, we predict that Ag5 clusters are capable of promoting defect-induced polarons transfer from the subsurface to the surface sites of reduced TiO2 samples. For both planar and pyramidal Ag5 clusters, and considering four different positions of bridging oxygen vacancies, we model up to 14 polaronic structures, leading to 134 polaronic states. About 71% of these configurations encompass coexisting surface polarons. The most stable states are associated with large inter-polaron distances (>7.5 Å on average), not only due to the repulsive interaction between trapped Ti3+ 3d1 electrons, but also due to the interference between their corresponding electronic polarization clouds [P. López-Caballero et al., J. Mater. Chem. A 8, 6842–6853 (2020)]. As a result, the most stable ferromagnetic and anti-ferromagnetic arrangements are energetically quasi-degenerate. However, as the average inter-polarons distance decreases, most (≥70%) of the polaronic configurations become ferromagnetic. The optical excitation of the midgap polaronic states with photon energy at the end of the visible region causes the enlargement of the polaronic wave function over the surface layer. The ability of Ag5 atomic clusters to stabilize multiple surface polarons and extend the optical response of TiO2 surfaces toward the visible region bears importance in improving their (photo-)catalytic properties and illustrates the potential of this new generation of subnanometer-sized materials. [ABSTRACT FROM AUTHOR]

Size-selected iron oxide nanoclusters are outstanding candidates for technological-oriented applications due to their high efficiency-to-cost ratio. However, despite many theoretical studies, experimental works on their oxidation mechanism are still limited to gas-phase clusters. Herein we investigate the oxidation of graphene-supported size-selected Fen clusters by means of high-resolution X-ray Photoelectron Spectroscopy. We show a dependency of the core electron Fe 2p3/2 binding energy of metallic and oxidized clusters on the cluster size. Binding energies are also linked to chemical reactivity through the asymmetry parameter which is related to electron density of states at the Fermi energy. Upon oxidation, iron atoms in clusters reach the oxidation state Fe(II) and the absence of other oxidation states indicates a Fe-to-O ratio close to 1:1, in agreement with previous theoretical calculations and gas-phase experiments. Such knowledge can provide a basis for a better understanding of the behavior of iron oxide nanoclusters as supported catalysts. Iron oxide nanoclusters are of interest for a broad range of applications, but limited experimental information on their oxidation mechanism is available outside of the gas phase. Here, the oxidation of graphene-supported size-selected Fen clusters is studied using high-resolution X-ray Photoelectron Spectroscopy. [ABSTRACT FROM AUTHOR]

The equilibrium structural parameters, symmetry groups, and dipole moments of the free hollow electron‐deficient TlBi19, Tl2Bi18, p‐, m‐, o‐Tl2Pb10 shells and the endohedral (He, Ne)@Tl2Pb10, (Y, La, Lu, Tl, Bi, Ce)@TlPb11, Tl@(Y, La, Lu) Pb11, Sr@TlBi19, Tl@SrBi19, Yb@TlBi19, Tl@YbBi19, [Y@TlBi19]+, [Lu@TlBi19]+, Sr@Tl2Bi18, and Yb@Tl2Bi18 complexes are predicted by using DFT (U)PBE0 hybrid method. The isomerization of (Sr, Yb)@TlkBi20–k into Tl@(Sr, Yb) Tlk–1Bi20–k is endothermic. The isodesmic substitution of an endo‐atom in the Tl@TlPb11 cluster for a rare‐earth atom is exothermic. The hollow TlkBi20–k (Sr, Yb) complexes with Tl in the shell and with Sr or Yb exo‐atom are impossible. The endo‐atoms plunge in hollow TlPb11 and hollow TlBi19 shells without delay on its surface. The (C5v)‐TlPb11 and (C3v)‐TlBi19 shells are stabilized by an endo‐atom X with oxidation number ΞX = +3 and +2, respectively. No one cerium IV oxidation state has been predicted. The integer number ΞX is presented as a function of the populations of one‐electron states in the shell surrounding the endo‐atom X. Each Pb or Bi atom in the electron‐deficient clusters retains an entirely localized lone electron pair. The change in the IR spectrum when a metal atom is embedded into its cavity indicates a strong interaction between the components of the endohedral complex. Structural aspects of the β‐decay of a radioactive endo‐atom in the cavity of a metal cluster are discussed. [ABSTRACT FROM AUTHOR]

C–O bond scission via photocatalysis is an important step in biomass depolymerization. Here, we demonstrate the scission of strong ether C–O bonds promoted by low-work-function Cd single atoms and clusters. Their loading on ZnS benefits C–H bond scission, thus weakening the C–O bond for chemical bond breaking. [ABSTRACT FROM AUTHOR]

Semiconductor materials anchored with transition metal cluster are promising photocatalysts for photocatalytic hydrogen evolution. In this paper, Co, N-co-doped graphene modified thin mesoporous carbon nitride (Co-NG/TMCN) was be synthesized through electrostatic adsorption treatment. Extensive characterization was used to explore the morphology, structures and optical properties of the as-prepared photocatalysts. The 10 wt% Co-NG/TMCN exhibited the high photocatalytic hydrogen evolution rate (2949 μmol g−1) within 4 h visible light irradiation, which was about 113 times than that of the pure TMCN (26 μmol g−1). Co-NG material with excellent electrical conductivity played a major role in accelerating charge transfer from TMCN material to cobalt atomic clusters. The photocatalytic hydrogen evolution performance of Co-NG/TMCN material was effectively improved. Consequently, a feasible approach for doping transition metal clusters to enhance photocatalytic activity was provided. • The introduction of cobalt atomic clusters provided more active sites. • The synergy between Co, N-co-doped graphene and thin mesoporous carbon nitride was beneficial to the ficient separation of photogenerated electrons. • The low content cobalt atomic clusters were efficiently utilized to increase hydrogen production rate. [ABSTRACT FROM AUTHOR]

The development of highly ultraviolet (UV) and near-infrared (NIR) absorbent transparent coatings is an important enabling technology and area of research for environmental sustainability and energy conservation. Different amounts of K4[{Nb5TaXi12}Xa6] cluster compounds (X = Cl, Br) dispersed into polyvinylpyrrolidone matrices were prepared by a simple, nontoxic and low-cost wet chemical method. The resulting solutions were used to fabricate visibly transparent, highly UV and NIR absorbent coatings by drop casting. The properties of the solution and films were investigated by complementary techniques (optical absorption, electrospray ionization mass spectrometry and Raman spectroscopy). The UV and NIR absorption of such samples strongly depended on the concentration, dispersion and oxidation state of the [{Nb5TaXi12}Xa6] nanocluster-based units. By varying and controlling these parameters, a remarkable improvement of the figures of merit TL/TE and SNIR for solar-glazing applications was achieved compared to the previous results on nanocomposite coatings based on metal atom clusters. [ABSTRACT FROM AUTHOR]

This review is dedicated to various functional nanoarchitectonic nanocomposites based on molecular octahedral metal atom clusters (Nb6, Mo6, Ta6, W6, Re6). Powder and film nanocomposites with two-dimensional, one-dimensional and zero-dimensional morphologies are presented, as well as film matrices from organic polymers to inorganic layered oxides. The high potential and synergetic effects of these nanocomposites for biotechnology applications, photovoltaic, solar control, catalytic, photonic and sensor applications are demonstrated. This review also provides a basic level of understanding how nanocomposites are characterized and processed using different techniques and methods. The main objective of this review would be to provide guiding significance for the design of new high-performance nanocomposites based on transition metal atom clusters. [ABSTRACT FROM AUTHOR]

We have developed an integrated instrument system of a multiple-ion laminar flow tube (MIFT) reactor combined with a tandem quadrupole mass spectrometer (TQMS) and soft-landing deposition (SD) apparatus. A customized water-cooling magnetron sputtering (MagS) source is designed, by which we are able to attain a highly efficient preparation of metal clusters of 1–30 atoms with tunable size distributions. Following the MagS source, a laminar flow tube reactor is designed, allowing for sufficient gas–collision reactions of the as-prepared metal clusters, which is advantageous for probing magic clusters and minimizing wall effects when probing the reaction dynamics of such clusters. The customized TQMS analyzer involves a conical octupole, two linear octupoles, a quadruple ion deflector, and a 19 mm quadruple mass analyzer, allowing to decrease the pressure stepwise (from ∼5 to ∼10−9 Torr), thus ensuring high sensitivity and high resolution of the mass spectrometry analysis. In addition, we have designed a dual SD apparatus for the mass-selected deposition of clusters and their reaction products. For the whole system, abbreviated as MagS-MIFT-TQMS-SD, we have performed a detailed ions-fly simulation and quantitatively estimated the ions transfer efficiency under vacuum conditions determined by real experiments. Taking these advantages, well-resolved Pbn+, Agn+, and Nbn+ clusters have been produced, allowing for meticulous studies of cluster reactions under sufficient gas-phase collisions free of electric field trapping. Also, we have tested the efficiency of the dual SD. [ABSTRACT FROM AUTHOR]

[Display omitted] • After the dissociation and diffusion of H 2 , the spillover of H atoms and H clusters is formed. • H cluster facilitated C-O bond scission to easily form H ligand co-bonded to metal. • There are four potential driving forces capable of dissociating CO 2. • Out of the various forces, atomic H is the most dominating force for the dissociation of CO 2. • The active sites and metal species strongly influence CO 2 dissociation route. The study of carbon dioxide (CO 2) methanation mechanisms widely argues on the nature and formation of intermediates. How reactants dissociate is still poorly understood. To gain deeper knowledge on its mechanism, we focused on studying reactants dissociation. After H 2 dissociation and diffusion, the spillover H atom was observed, as well as the confirmation of H cluster formation on metal through aggregation by simulation and experiment. This H cluster facilitated C-O bond scission to easily form H ligand cobonded to metal, and thus resulted in high CO 2 methanation performance. Four driving forces could dissociate CO 2 , three of them came from supports and metals, and another one was atomic H on metal as the strongest force. This simple and convenient method has wide adaptability and can be developed as an effective standard method for studying CO 2 dissociation. The facile dissociation study of reactants would be very helpful in understanding the CO 2 hydrogenation mechanism. [ABSTRACT FROM AUTHOR]

An all-electron calculation on Be n Si (n = 1–12) clusters has been performed by using density functional theory with the generalized gradient approximation at the PW91 level. The results reveal that the lowest energy geometries of Be n Si (n = 1–12) clusters may be generated by substituting a Si atom for one Be atom of the Be n +1 clusters. In addition, Si atom tends to occupy external locations of main Be n clusters and bonds with multiple Be atoms in the Be n Si (n > 2) clusters. The average binding energy of Be n Si clusters is higher than that of pure Be n +1 clusters, indicating that the doped of the Si atom enhances the cluster's binding force. Compared with pure Be n +1 clusters, the HOMO-LUMO GAP of Be 7 Si, Be 8 Si, and Be 10 Si clusters increase while the HLG of other Be n Si clusters(n = 1–3,5,9,11,12) decreas. The vertical ionization potential and vertical electron affinities curves of clusters have the same general trend. The VIP of the cluster decreases gradually while the VEA increases gradually. The doping of the Si atom greatly influences the stability of pure Be n clusters, and the analysis of energy and electronic properties of Be n Si clusters reveals that the Be 3 Si cluster is the magic number structure in the system. [ABSTRACT FROM AUTHOR]

Atomic Pd x Au y (1 ≤ x + y ≤ 4) clusters are decorated on polyaniline to be used as the catalytic electrode in electrochemical sensors. The current responses in the oxidation of 1-propanol are used to reveal the catalytic activity. Effects of the size, decoration sequence, and composition of the atomic metal clusters decorated on the PANI on the catalytic activity are evaluated. Regarding the size, an odd-even size effect is observed in the atomic pure metal clusters, which the even-numbered pure metal clusters show a higher catalytic activity than the odd-numbered pure metal clusters. For the decoration sequence, the catalytic activity is high when the same metal is decorated in the first two cycles of the cyclic atomic electrodeposition process. For the composition effect, the atomic metal clusters show a high catalytic activity in the oxidation, in the region of second oxidation peak, when there are more Au in the atomic metal clusters. [Display omitted] • Atomic Pd x Au y (1 < x + y < 4) clusters are decorated on PANI toward 1-propanol oxidation. • Atomic pure Pd and Au clusters both show the odd-even effect. • Effects of the decoration sequence and composition are studied. • Decorating the same metal in the first 2 cycles result a better catalytic activity. • Clusters of more Pd show a low catalytic activity in the second oxidation peak. [ABSTRACT FROM AUTHOR]

The fine structures of palladium-silver bimetallic clusters are central to understand their structure–activity relationship. However, depending on the number of metal atoms considered, the corresponding structures of pure clusters may become prohibitively high, let alone mentioning doped atoms. Herein, the nucleation and growth mechanisms of PdmAgn (m + n ≤ 13) clusters, which is deliberate because 13 is the first magic number for many transition-metal clusters, are studied by theoretical calculations in the form of 'Yang Hui Triangle.' The optimal nucleation and growth paths of the palladium-silver bimetallic clusters are obtained and found to be strongly dependent on their compositions. Based on this, the role of silver atoms in the bimetallic clusters is explored in depth. It is found that Ag atom has the influence on the clusters, both ensemble (geometric) and ligand (electronic) effects. The geometric structures are affected by a counterbalance between the Pd–Pd, Pd–Ag and Ag–Ag interactions. With the doping of Ag atoms, the bimetallic clusters experienced a conspicuous structural evolution, and the electron population is anisotropic. The partial density of state (PDOS) analysis shows that the electronic interaction between Pd and Ag atoms is mainly the respective d electrons. No matter from the point of view of the energy or electron, the composition with the best stabilization is found to be Pd5Ag8. [ABSTRACT FROM AUTHOR]

High‐nuclearity clusters resemble the closest model between the determination of atomically precise chemical species and the bulk metallic version thereof, and both impacts on a variety of applications, including catalysis, optics, sensors, and new energy sources. Our interest lies with the nanoclusters of the Group 11 (Cu, Ag, Au) metals stabilized by dichalcogenido and hydrido ligands. Herein, we describe superatoms formed by the clusters and their relationship with precursor hydrido clusters. Specifically, our concept seeks to demonstrate a possible correlation that exist between hydrido clusters (and nanoalloys) and the formation of superatoms, with the loss of hydrides and typically with release of H2 gas. These reactions appear to be internal self‐redox reactions and require no additional reducing agent, but does seem to require a similar core structure. Knowledge of such processes could provide insight into how clusters grow and an understanding in bridging the atomically precise cluster – metal nanoparticle mechanism. [ABSTRACT FROM AUTHOR]

In this work, we explored the energetic landscape of Au–Ag bimetallic clusters with Au3Agm, Au4Agm, and Au5Agm compositions (3 ≤ m ≤ 17) using the combined GA-DFT (genetic algorithm-density functional theory) methodology. All structures were divided into three series (Au3Agm, Au4Agm, and Au5Agm), and each series was divided into different groups depending on the Au atom position in the cluster. The most stable clusters (Au3Ag15, Au4Ag15, and Au5Ag11) have π-electron delocalization systems, which induce a spatial aromaticity in these structures. [ABSTRACT FROM AUTHOR]

Coordination of tin(II) phthalocyanine to transition metal carbonyl clusters in neutral {SnII(Pc2−)}0 or radical anion {SnII(Pc˙3−)}− states is reported. Direct interaction of Co4(CO)12 with {SnII(Pc2−)}0 yields a crystalline complex {Co4(CO)11·SnII(Pc2−)} (1). There is no charge transfer from the cluster to phthalocyanine in 1, which preserves the diamagnetic Pc2− macrocycle. The Ru3(CO)12 cluster forms complexes with one or two equivalents of {SnII(Pc˙3−)}− to yield crystalline {Cryptand[2.2.2](Na+)}{Ru3(CO)11·SnII(Pc˙3−)}− (2) or {Cryptand[2.2.2](M+)}2{Ru3(CO)10·[SnII(Pc˙3−)]2}2−·4C6H4Cl2 (3) (M+ is K or Cs). Paramagnetic {SnII(Pc˙3−)}− species in 2 are packed in π-stacking [{SnII(Pc˙3−)}−]2 dimers, providing strong antiferromagnetic coupling of spins with exchange interaction J/kB = −19 K. Reduction of Ru3(CO)12, Os3(CO)12 and Ir4(CO)12 clusters by decamethylchromocene (Cp*2Cr) and subsequent oxidation of the reduced species by {SnIVCl2(Pc2−)}0 yield a series of complexes with high-spin Cp*2Cr+ counter cations (S = 3/2): (Cp*2Cr+){Ru3(CO)11·SnII(Pc˙3−)}−·C6H4Cl2 (4), (Cp*2Cr+){Os3(CO)10Cl·SnII(Pc˙3−)}−·C6H4Cl2 (5) and (Cp*2Cr+){Ir4(CO)11·SnII(Pc˙3−)}2− (6). It is seen that reduced clusters are oxidized by SnIV, which is transferred to SnII, whereas the Pc2− macrocycle is reduced to Pc˙3−. In the case of Os3(CO)12, oxidation of the metal atom in the cluster is observed to be accompanied by the formation of Os3(CO)10Cl with one OsI center. Rather weak magnetic coupling is observed between paramagnetic Cp*2Cr+ and {SnII(Pc˙3−)}− species in 4, but this exchange interaction is enhanced in 5 owing to Os3(CO)10Cl clusters with paramagnetic OsI (S = 1/2) also being involved in antiferromagnetic coupling of spins. The formation of {SnII(Pc˙3−)}− with radical trianion Pc˙3− macrocycles in 2–5 is supported by the appearance of new absorption bands in the NIR spectra and essential Nmeso–C bond alternation in Pc (for 3–5). On the whole, this work shows that both diamagnetic {SnII(Pc2−)}0 and paramagnetic {SnII(Pc˙3−)}− ligands substitute carbonyl ligands in the transition metal carbonyl clusters, forming well-soluble paramagnetic solids absorbing light in the visible and NIR ranges. [ABSTRACT FROM AUTHOR]

[Display omitted] • A comprehensive summary of advances in metal cluster superatoms. • Superatomic features of transition metal clusters, electronic open- and closed shells, aromaticity, and magnetism. • A summary of the principles and theoretical modeling around superatoms. • A four-dimensional image for the 3D periodic table of elements, providing convenience for tailoring cluster-genetic materials. Clusters that mimic elemental atoms in the periodic table are known as superatoms which open up a new window to design functional materials and catalysts by atomic construction. Ongoing continuous efforts have been devoted to exploring active/inert superatoms in the gas phase and synthesizing ligand-protected metal cluster superatoms and superatomic solids. Here we summarize recent research progress of superatom chemistry and elucidate the accommodation of delocalized electrons in stabilizing metal clusters, especially the superatomic orbitals formed by d-electrons of the transition metals. We highlight the typical superatomic features of electronic open- and closed shells, aromaticity, and magnetism especially for the clusters of nonmagnetic elements. We propose a four-dimensional image for the future three-dimensional periodic table of elements, endeavoring to provide a convenient reference for designing and tailoring cluster-genetic materials. [ABSTRACT FROM AUTHOR]

Endohedral Zintl clusters—multi-metallic anionic molecules in which a d-block or f-block metal atom is enclosed by p-block (semi)metal atoms—are very topical in contemporary inorganic chemistry. Not only do they provide insight into the embryonic states of intermetallic compounds and show promise in catalytic applications, they also shed light on the nature of chemical bonding between metal atoms. Over the past two decades, a plethora of endohedral Zintl clusters have been synthesized, revealing a fascinating diversity of molecular architectures. Many different perspectives on the bonding in them have emerged in the literature, sometimes complementary and sometimes conflicting, and there has been no concerted effort to classify the entire family based on a small number of unifying principles. A closer look, however, reveals distinct patterns in structure and bonding that reflect the extent to which valence electrons are shared between the endohedral atom and the cluster shell. We show that there is a much more uniform relationship between the total valence electron count and the structure and bonding patterns of these clusters than previously anticipated. All of the p-block (semi)metal shells can be placed on a ladder of total valence electron count that ranges between 4n +2 (closo deltahedra), 5n (closed, three-bonded polyhedra) and 6n (crown-like structures). Although some structural isomerism can occur for a given electron count, the presence of a central metal cation imposes a preference for rather regular and approximately spherical structures which maximise electrostatic interactions between the metal and the shell. In cases where the endohedral metal has relatively accessible valence electrons (from the d or f shells), it can also contribute its valence electrons to the total electron count of the cluster shell, raising the effective electron count and often altering the structural preferences. The electronic situation in any given cluster is considered from different perspectives, some more physical and some more chemical, in a way that highlights the important point that, in the end, they explain the same situation. This article provides a unifying perspective of bonding that captures the structural diversity across this diverse family of multimetallic clusters. [ABSTRACT FROM AUTHOR]

Graphene can be widely utilized as a substrate to support various transition metal (TM) nanoclusters or nanoparticles for surfaced‐supported catalysis, such as electrocatalysis or photovoltaics. The subtle interactions between TM and graphene carbon atoms are expected to be crucial in TM–graphene nanocomposites to affect their growth morphologies and final functionalities. Here, the morphology evolution and catalytic ability of five ultrafine TM (Zn, Cu, Fe, Ni, and Ru) clusters with 48 atoms on graphene etching are investigated by using ab initio molecular dynamics (AIMD) simulations. It is found that three factors, i.e., TM cluster type, operation temperature, and graphene edge type, play important roles in the catalytic behaviors of TM clusters for heat‐induced graphene etching. The results are helpful in locating the catalytic performance of TM clusters in graphene cutting and ensuring stability of TM–graphene nanocomposites in device applications. [ABSTRACT FROM AUTHOR]

Designing the novel cluster units is a major concern in the cluster assembled materials. With the aid of particle swarm optimization algorithm and density functional theory calculations, we have identified the geometric and electronic structures of 13-atom MgnLi12−nSc (n = 1–8) nanoclusters. The icosahedral structures are discovered as their respective global minima except Mg8Li4Sc, of which the cage structure is destroyed due to a magnesium atom outside the external metal cage. As the magnesium atoms increases, there is a sharp energy drop thereafter Mg5Li7Sc, and a large gain energy in MgnLi12−nSc (n = 3–5) is indicative of their especial stability. Molecular orbital analysis shows that the high stable clusters have the characteristics of magnetic superatoms. Then, the second stable magnetic cluster of Mg4Li8Sc is chosen as a possible building unit and the five-membered face-sharing motif is adopted. Mg4Li13Sc2 with the supermolecular properties are successfully constructed. Though the outer cage doped, this could to be a useful way to form the magnetic superatoms. Our findings further enrich building units that may aid in developing cluster-materials and tailoring their properties. [ABSTRACT FROM AUTHOR]

Metal-atom-modified nitrogen-doped carbon materials (M-N-C) have emerged as promising candidates for electro-Fenton degradation of pollutants. Nonetheless, a comprehensive exploration of size-dependent M-N-C catalysts in the electro-Fenton process remains limited, posing challenges in designing surface-anchored metal species with precise sizes. Herein, a heterogeneous-homogeneous coupled electro-Fenton (HHC-EF) system was designed and various M-N-C catalysts anchored with Co single atoms (CoSA-N-C), Co clusters (CoAC-N-C), and Co nanoparticles (CoNP-N-C) were successfully synthesized and employed in an HHC-EF system. Intriguingly, CoAC-N-C achieved outstanding removal efficiencies of 99.9% for BPA and RhB within 10 and 15 min, respectively, with the fastest reaction kinetics (0.70 min−1 for BPA and 0.34 min−1 for RhB). Electron spin resonance and trapping experiments revealed that·OH played a crucial role in the HHC-EF process. Moreover, experiments and theoretical calculations revealed that the unique metallic size effect facilitate the in-situ electro-generation of H 2 O 2. Specifically, the atomic interaction between neighboring Co atoms in clusters enhanced O 2 adsorption and activation by strengthening the Co-N bond and transforming O 2 adsorption configuration to the Yeager-type. This study provides valuable insights that could inspire the size-oriented metal-based catalyst design from the perspective of the potential atomic distance effect. [Display omitted] • Various Co-sized N-C catalysts were delicately designed for electro-Fenton degradation of aromatic compound. • Atom-dispersed Co cluster on N-C exhibited the excellent removal efficiency of BPA and RhB with high stability and economy. • The·OH was identified as dominant active radical species, participated in electro-Fenton process. • The metallic size effect in Co clusters induced a switch of O 2 adsorption configuration to bridged type. [ABSTRACT FROM AUTHOR]

Modulating the electronic properties of single-atomic metal sites with metal clusters is a promising strategy for boosting their intrinsic oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activity. Herein, we report an effective isolation-confinement strategy for synthesis of well-dispersed Fe-Co atom clusters and N 4 Fe-CoN 4 atomic pair sites on carbon nanofibers (marked as β-FeCo-PCNF), in which the addition of β-cyclodextrin is crucial in avoiding the agglomeration of metal species. The Fe-Co atomic clusters induce a downward shift in the d -band center of Fe-Co atomic sites, and this shift effectively reduces the adsorption energy of OOH* on Fe-Co atomic sites, resulting in lower energy barriers for ORR and OER. Remarkably, the β-FeCo-PCNF-based Zn-air battery exhibits excellent power density and cycling stability. This work paves the way for a universal strategy to regulate the electronic localization of atomic pair sites by alloy clusters and provides essential guidance for designing multifunctional electrocatalysts. [Display omitted] • β-cyclodextrin prevents metal agglomeration. • Fe-Co atomic pair sites and Fe-Co alloy clusters anchored to carbon nanofibers. • Fe-Co alloy clusters modulate the d -band center of Fe-Co atomic sites. • The assembled Zn-air battery exhibits excellent power density and cycling stability. [ABSTRACT FROM AUTHOR]

The design of metal–organic frameworks (MOFs) that incorporate more than one metal cluster constituent is a challenging task. Conventional one‐pot reaction protocols require judicious selection of ligand and metal ion precursors, yet remain unpredictable. Stable, preformed nanoclusters, with ligand shells that can undergo additional coordination‐driven reactions, provide a platform for assembling multi‐cluster solids with precision. Herein, a discrete Co6S8(PTA)6 (PTA=1,3,5‐triaza‐7‐phosphaadamantane) superatomic‐metalloligand is assembled into a three‐dimensional (3D) coordination polymer comprising Cu4I4 secondary building units (SBUs). The resulting heterobimetallic framework (1) contains two distinct cluster constituents and bifunctional PTA linkers. Solid‐state diffuse reflectance studies reveal that 1 is an optical semiconductor with a band‐gap of 1.59 eV. Framework‐modified electrodes exhibit reversible redox behavior in the solid state arising from the Co6S8 superatoms, which remain intact during framework synthesis. [ABSTRACT FROM AUTHOR]

Building framework materials with desirable properties and enhanced functionalities with nanocluster/superatom complexes as building blocks remains a challenge in the field of nanomaterials. In this study, the chiral [Au1Ag22(S‐Adm)12]3+ nanocluster/superatom complex (SC, in which S‐Adm=1‐adamantanethiol) was employed as a building block to construct the three‐dimensional (3D) superatom complex inorganic framework (SCIF) materials SCIF‐1 and SCIF‐2 through inorganic SbF6− linkers. SCIF‐1 is racemic due to the assembly of two SC enantiomers in a single crystal. In SCIF‐2, the SC enantiomers are packed in separate crystals, thus producing larger channels and a circularly polarized luminescence (CPL) response. These two 3D SCIF materials exhibit unique sensitive photoluminescence (PL) in protic solvents. Our study provides a new pathway for creating novel open‐framework materials with superatom complexes and a foundation for the further development of 3D framework materials for sensing and other applications. [ABSTRACT FROM AUTHOR]

Metal superatomic nanoclusters, with electronic structures similar to those of one certain atom, are an important type of metal clusters. Interestingly, metal clusters with metal cores composed of either icosahedral M13 or icosahedral assemblies always have a greater potential to become superatomic clusters. Furthermore, superatomic clusters with similar electronic compositions could possess various geometric structures, owing to differences in the shells; this provides a deeper understanding of the metal superatomic cluster and the assembly for nanomaterials. Therefore, this review focuses on the geometric and electronic structures of gold/silver superatomic clusters based on icosahedron M13 units and their alloys, which will facilitate the development of various applications of superatomic clusters. [ABSTRACT FROM AUTHOR]