A homoleptic alkynyl-protected [Ag9Cu6( t BuC[triple bond, length as m-dash]C)12]+ superatom with free electrons: synthesis, structure analysis, and different properties compared with the Au7Ag8 cluster in the M15 + series

Construction of Atomic-Scale Compressive Strain for Oxime Electrosynthesis

Tuning the surface strain is a powerful strategy to enhance the catalytic activity of metal nanocatalysts, yet an atomically precise catalyst with intramolecular strain to unlock the atomic-level strain-structure-activity relationship is still highly desired. Herein, we report the synthesis, structural anatomy, and catalytic performance toward cyclohexanone oxime electrosynthesis of an atomically precise Ag16Cu18(C≡C-C6H11)24 (Ag16Cu18) nanocluster, which has a Cu6 ring in the center. The Cu-Cu distance in the Cu6 ring is only 1.616 Å in a single crystal, the shortest Cu-Cu bond in Cu nanomaterials to date. Furthermore, once Ag16Cu18 was loaded onto carbon paper, the ultrashort Cu-Cu bond elongated to ∼2.40 Å, still showing strong intramolecular compressive strain. Ag16Cu18 exhibited excellent catalytic activity toward oxime electrosynthesis, manifested by a maximal Faradaic efficiency, yield, and yield rate of cyclohexanone oxime reaching 47.4%, 95.4%, and 2.66 mmol·h-1·cm-2 at -0.35 V, respectively. In-situ attenuated total reflection surface-enhanced infrared spectroscopy revealed that the Cu sites adjacent to the Ag atoms primarily reduce NO and stabilize it at the *NH2OH stage, while the Cu sites with compressive strain provide H* for NO reduction and adsorb cyclohexanone to react with *NH2OH, forming cyclohexanone oxime simultaneously. Density functional theory calculations confirmed the presence of compressive strain in the Cu6 ring, which facilitates H* formation and cyclohexanone adsorption, hence significantly contributing to oxime generation. This study not only reports a case of atomically precise clusters with intramolecular compressive strain but also provides an atomic-level understanding for employing bimetallic nanocluster-based catalysts toward the electrosynthesis of valuable organic molecules.

An atomically precise alloy AgCu cuboid nanocluster with a cubic core: gram scale synthesis, total structure, electronic structure, and catalytic performance

Although atomically precise noble metal nanoclusters (NMNCs) are highly desirable to unravel the size and structure-activity relationships in catalysis, their synthesis in a controlled way at the atomic level is challenging. Herein, we report the structure and gram scale synthesis of a highly symmetric 2-phenylethanethiol (PETH) and triphenylphosphine (PPh3)-protected AgCu alloy nanocluster (NC) [Ag4Cu28H6(PET)16Cl8(PPh3)8][BF4]2 with a cuboid shape, denoted as Ag4Cu28. This was accomplished via a facile one-pot reduction method. The Ag4Cu28 NC consists of an Ag4Cu4 metal core, six hydrides, four Cu4Cl2 units, eight PET ligands, and four Cu2(PET)2(PPh3)2 motifs. High-resolution electrospray ionization mass spectrometry (HRESI MS) and density functional theory (DFT) calculations support this crystal structure. Moreover, Ag4Cu28 exhibits excellent catalytic activity (k = 7.86 min-1) in the hydrogenation of hazardous nitroarenes. This intriguing NC delivers a unique opportunity to explore the gram scale synthesis of alloy nanoclusters and to expand the research on Cu and Ag-based NCs.

Ferrocene-Functionalized Atomically Precise Metal Clusters Exhibit Synergistically Enhanced Performance for CO2 Electroreduction

The integration of organometallic compounds with metal nanoparticles can, in principle, generate hybrid nanocatalysts endowed with augmented functionality, presenting substantial promise for catalytic applications. Herein, we synthesize an atomically precise metal cluster (Ag9Cu6) catalyst integrated with alkynylferrocene molecules (Ag9Cu6-Fc). This hybrid catalyst design facilitates a continuous electron transfer channel via an ethynyl bridge and establishes a distinctive local chemical environment, resulting in remarkably enhanced catalytic activity in CO2 electroreduction. The Ag9Cu6-Fc catalyst achieves a record-high product selectivity of CO Faradaic efficiency of 100 % and an industrial-level CO partial current density of -680 mA/cm2, surpassing the performance of the Ag9Cu6 cluster (62 % and -230 mA/cm2, respectively) without ferrocene functionalization in a membrane electrode assembly cell. Operando experimental and computational findings offer valuable insights into the role of ferrocene functionalization in synergistically improving the catalytic performance of metal clusters, propelling the advancement of metallic-organometallic hybrid nanoparticles for energy conversion technologies.

Assembly of silver(I)-copper(I) bimetallic thiolate complexes assisted by phenylacetylene stabilizers

AgI/CuI bimetallic clusters have been widely reported, but synthesis of such clusters via simple self-assembly of heterometallic ions in air remains challenging due to the susceptibility of CuI ions to oxidation. In this study, protected by the phenylacetylene auxiliary ligand, we utilized [Cu(CH3CN)4]PF6 in conjunction with the (iPrSAg)n polymer to form Ag(I)-Cu(I) oligomer precursors, serving as the starting point for constructing a new [Ag11-xCux(iPrS)9(DPPM)3](PF6)2 cluster (DPPM = bis(diphenylphosphino)methane, Ag11-xCux, x = 5-9). When the (iPrSAg)n precursor was replaced by (tBuSAg)n, another cluster [Ag21Cu4S2(tBuS)18(CH3CN)4](CH3OH)2(H3O)(PF6)4 (Ag21Cu4) was obtained. By combining crystallographic data and electrospray ionization mass spectrometry (ESI-MS) results, the compositions and structures of these two new clusters were determined. Additionally, the optical physical properties of the luminescent Ag11-xCux were investigated, showing red phosphorescence emission in both solid-state and solution phases. The solid-state phosphorescence quantum yield (QY) is 8%, with a lifetime of 7.2 μs. These findings suggest that phenylacetylene auxiliary ligands can effectively stabilize CuI ions and guide the assembly of silver-copper bimetallic thiolate motifs into new compounds under ambient conditions.

Anomalous Structural Transformation of Cu(I) Clusters into Multifunctional CuAg Nanoclusters

We report an anomalous structural transformation of a Cu(I) cluster into two different types of copper-silver (CuAg) alloy nanoclusters. Different from previous reports, we demonstrate that under specifically designed reaction conditions, the Ag-doping could induce a substantial growth of the starting Cu15 and a Ag13Cu20 nanocluster was obtained via the unexpected insertion of an Ag13 kernel inside the Cu(I)-S shell. Ag13Cu20 demonstrates high activity to initiate the photopolymerization of previously hard-to-print inorganic polymers in 3D laser microprinting. Interestingly, a slight modification of the reaction condition leads to the formation of another Ag18-xCuxS (8≤x) nanocluster templated by a central S2- anion, which possesses a unique electronic structure compared to conventional template-free CuAg nanoclusters. Overall, this work unveils the intriguing doping chemistry of Cu clusters, as well as their capability to create different types of alloy nanoclusters with previously unobtainable structures and multifunctionality.

An Au5Ag12(SR)9(dppf)4 alloy nanocluster: structural determination and optical property and photothermal conversion investigation

Photothermal conversion has garnered significant attention due to its potential for efficient energy conversion and application in targeted therapies. However, controlling photothermal properties at the atomic level remains a challenge in current materials synthesis. In this study, we report the synthesis and structural determination of a phosphine and mercaptan co-protected Au5Ag12(SR)9(dppf)4 (Au5Ag12) nanocluster with an extremely low quantum yield (∼0%). For comparative purposes, we synthesized three alloy nanoclusters of similar size. Notably, Au5Ag12 demonstrates a remarkably superior photothermal conversion performance, significantly outperforming the other clusters. We investigated this variance from both absorption and emission perspectives. This research not only opens new avenues for the application of clusters with extremely low quantum yields, but also provides experimental evidence for understanding the photothermal conversion properties of cluster materials at the atomic level.

Supramolecularly Dimeric Assemble of Planar Cu13 Clusters Controlled by the Length of Spacers of Diphosphine

The controlled formation of dimeric clusters is challenging. Three copper(I) clusters, labeled as {Cu13[o-Ph(C≡C)2]6(L)4}(ClO4), were synthesized by using three different ligands, including 1,4-bis(diphenylphosphino)butane (dppb), 1,5-bis(diphenylphosphino)pentane (dpppe), and bis(diphenylphosphino)hexane (dpph). By increasing the flexibility of alkyl spacers in the diphosphine ligands, the relative positions of the phenyl rings could be optimized to achieve efficient packing with maximized intercluster interactions. In the crystal structures, cluster 1 with dppb ligands did not display interlocked structures. In contrast, cluster 2 with dpppe ligands formed supramolecularly interlocked polymers through weak π-π interactions and C-H···π interactions, while cluster 3 employing dpph ligands formed supramolecularly interlocked dimers with strong π-π interactions and C-H···π interactions. The supramolecular dimer of 3 was also evidenced by analyses through electrospray ionization mass spectrometry and transmission electron microscopy. Density functional theory calculation was used to understand the electronic structure and transitions. Supramolecularly interlocked polymers/dimers with rigid structures exhibited higher quantum efficiency. The solution of these clusters demonstrated remarkable aggregation-induced emission enhancements. This study presents unique examples of planar luminescent copper clusters, featuring the first serial dialkynyl-protected cluster. It underlines the importance of ligand flexibility in creating supramolecular cluster dimers.

Ag6 Cu8 (C=CAr)14 (DPPB)2 : A Rigid Ligand Co-Protected Bimetallic Silver(I)-Copper(I) Cluster with Room-Temperature Luminescence

Metal clusters have become increasingly important in various applications, with ligands playing a crucial role in their construction. In this study, we synthesized a bimetallic cluster, Ag6 Cu8 (C=CAr)14 (DPPB)2 (Ag6 Cu8 ), using a rigid acetylene ligand, 3,5-bis(trifluoromethyl)phenylacetylide. Through single-crystal structure characterization, we discovered that the butterfly-shaped Ag2 Cu2 motifs were subject to distortion due to steric hindrance imposed by the rigid ligand. These motifs assembled together through shared vertices and edges. Mass spectrometry analysis revealed that the primary fragments detected during electrospray ionization (ESI) testing corresponded to the Ag2 Cu2 motifs. Furthermore, we conducted a comprehensive investigation of the cluster's solution properties employing 31 P NMR, UV-vis absorption, and photoluminescent measurements. In contrast to previously reported Ag/Cu bimetallic clusters protected by flexible ligands, Ag6 Cu8 protected by rigid ligands exhibited intriguing room temperature fluorescence properties alongside excellent thermal stability. DFT calculations on Ag6 Cu8 and Ag6 Cu8 with the rigid aromatic ring removed revealed that the presence of the rigid aromatic ring can lower the electronic energy levels of the cluster, and reduce the energy gap from 4.05 eV to 3.45 eV. Moreover, the rigid ligand further suppressed the non-radiative transition process, leading to room temperature fluorescence emission.

Hydride-doped Ag17Cu10 nanoclusters as high-performance electrocatalysts for CO2 reduction

The atomically precise metal electrocatalysts for driving CO2 reduction reactions are eagerly pursued as they are model systems to identify the active sites, understand the reaction mechanism, and further guide the exploration of efficient and practical metal nanocatalysts. Reported herein is a nanocluster-based electrocatalyst for CO2 reduction, which features a clear geometric and electronic structure, and more importantly excellent performance. The nanocatalysts with the molecular formula of [Ag17Cu10(dppm)4(PhC≡C)20H4]3+ have been obtained in a facile way. The unique metal framework of the cluster, with silver, copper, and hydride included, and dedicated surface structure, with strong (dppm) and labile (alkynyl) ligands coordinated, endow the cluster with excellent performance in electrochemical CO2 reduction reaction to CO. With the atomically precise electrocatalysts in hand, not only high reactivity and selectivity (Faradaic efficiency for CO up to 91.6%) but also long-term stability (24 h), are achieved.

Alkynyl-Protected Bimetallic Nanoclusters with a Hybrid Mackay Icosahedral Ag42 Cu12 Cl Kernel and an Octahedral Ag22 Cu12 Kernel

A facile strategy that directly reduces alkynyl-silver precursors and copper salts for the synthesis of bimetallic nanoclusters using the weak reducing agent Ph2 SiH2 is demonstrated. Two alkynyl-protected concentric-shell nanoclusters, (Ph4 P)2 [Ag22 Cu12 (C≡CR)28 ] and (Ph4 P)3 [Ag42 Cu12 Cl(C≡CR)36 ] (Ag22 Cu12 and Ag42 Cu12 Cl, R=bis(trifluoromethyl)phenyl), were successfully obtained and characterized by single-crystal X-ray diffraction and electro-spray ionization mass spectrometry. For the first time, a hybrid 55-atom two-shell Mackay icosahedron was found in Ag42 Cu12 Cl, which is icosahedral M54 Cl instead of M55 . The incorporation of a chloride in the metal icosahedron contributes to the stability of the cluster from both electronic and geometric aspects. Alkynyl ligands show various binding-modes including linear "RC≡C-Cu-C≡CR" staple motifs.

Quasi-Isomeric Anion-Templated Silver Nanoclusters: Effect of Bulkiness on Luminescence

Anion-templated silver nanoclusters are fascinating to study because of their diverse structures, which are dictated by the nature of both anions and ligands. Here, we used the bulky 1-ethynyladamantane as one of the protecting ligands alongside trifluoracetate to successfully synthesize a chlorine-templated silver nanocluster─Cl@Ag19(C12H15)11(C2O2F3)7. Elucidation of its structure by single crystal X-ray diffraction revealed the structure to be a chlorine-centered Ag19 cage with protection by alkynyl and carboxylic ligands. This cluster is non-emissive at room temperature and showed green emission with a large Stokes shift at low temperature. The crystal structure was found to be quasi-isomeric with a previously reported Ag19 cluster protected by tert-butyl acetylene, which is emissive at room temperature. Detailed photoluminescence studies and structure-property correlation revealed that the arrangement of the silver skeleton which is influenced by the bulky substituent of the ligand might be responsible for the difference in emission properties.

Sandwich-Kernelled AgCu Nanoclusters with Golden Ratio Geometry and Promising Photothermal Efficiency

Metal nanoclusters have recently attracted extensive interest from the scientific community. However, unlike carbon-based materials and metal nanocrystals, they rarely exhibit a sheet kernel structure, probably owing to the instability caused by the high exposure of metal atoms (particularly in the relatively less noble Ag or Cu nanoclusters) in such a structure. Herein, we synthesized a novel AgCu nanocluster with a sandwich-like kernel (diameter≈0.9 nm and length≈0.25 nm) by introducing the furfuryl mercaptan ligand (FUR) and the alloying strategy. Interestingly, the kernel consists of a centered silver atom and two planar Ag10 pentacle units with completely mirrored symmetry after a rotation of 36 degrees. The two Ag10 pentacles and some extended structures show an unreported golden ratio geometry, and the two inner five-membered rings and the centered Ag atom form an unanticipated full-metal ferrocene-like structure. The featured kernel structure causes the dominant radial direction transition of excitation electrons, as determined via time-dependent density functional theory calculations, which affords the protruding absorption at 612 nm and contributes to the promising photothermal conversion efficiency of 67.6 % of the as-obtained nanocluster, having important implications for structure-property correlation and the development of nanocluser-based photothermal materials.

DppfCuBH4: new reducing agents for the synthesis of ferrocene-functionalized metal nanoclusters

A facile synthesis of atomically precise metal nanoclusters, especially those decorated with functional groups, is the prerequisite for finding applications in special fields and studying structure-and-property relationships. The exploration of simple and efficient synthetic prototypes for introducing functional ligands (such as ferrocene) into cluster moieties is thus of high interest. In this work, a type of reducing agent of dppfCuBH₄ (dppf is 1,1'-bis(diphenyphosphino)ferrocene) is introduced for the first time to prepare ferrocene-functionalized metal nanoclusters. Two new clusters of [Ag₂₅Cu₄(dppf)₆(3-F-PhCC)₁₂Cl₆]³⁺ (1) and [Ag₄(dppf)₅Cl₂]²⁺ (2) have been obtained from the simple synthetic method. The two compounds have been fully characterized by advanced techniques of electrospray ionization mass spectroscopy (ESI-MS), nuclear magnetic resonance (NMR), and ultraviolet-visible spectroscopy (UV-Vis). The total structure of the clusters, as determined by X-ray single-crystal diffraction, describes the Ag₁₃@Ag₁₂Cu₄(dppf)₆(3-F-PhCC)₁₂Cl₆ core-shell structure of 1 and [Ag₂Cl(dppf)₂]⁺-dppf-[Ag₂Cl(dppf)₂]⁺ polymeric structure of 2. This work opens the door to employing dppfCuBH₄ as a functional reducing agent to discover many underlying metal nanoclusters and even other nanomaterials which feature ferrocene-groups.

Alkynyl-Protected Chiral Bimetallic Ag22 Cu7 Superatom with Multiple Chirality Origins

Understanding the origin of chirality in the nanostructured materials is essential for chiroptical and catalytic applications. Here we report a chiral AgCu superatomic cluster, [Ag₂₂ Cu₇ (C≡CR)₁₆ (PPh₃ )₅ Cl₆ ](PPh₄ ), Ag₂₂ Cu₇ , protected by an achiral alkynyl ligand (HC≡CR: 3,5-bis(trifluoromethyl)phenylacetylene). Its crystal structure comprises a rare interpenetrating biicosahedral Ag₁₇ Cu₂ core, which is stabilized by four different types of motifs: one Cu(C≡CR)₂ , four -C≡CR, two chlorides and one helical Ag₅ Cu₄ (C≡CR)₁₀ (PPh₃ )₅ Cl₄ . Structural analysis reveals that Ag₂₂ Cu₇ exhibits multiple chirality origins, including the metal core, the metal-ligand interface and the ligand layer. Furthermore, the circular dichroism spectra of R/S-Ag₂₂ Cu₇ are obtained by employing appropriate chiral molecules as optical enrichment agents. DFT calculations show that Ag₂₂ Cu₇ is an eight-electron superatom, confirm that the cluster is chirally active, and help to analyze the origins of the circular dichroism.

Body-Centered-Cubic-Kernelled Ag15Cu6 Nanocluster with Alkynyl Protection: Synthesis, Total Structure, and CO2 Electroreduction

While atomically monodisperse nanostructured materials are highly desirable to unravel the size- and structure-catalysis relationships, their controlled synthesis and the atomic-level structure determination pose challenges. Particularly, copper-containing atomically precise alloy nanoclusters are potential catalyst candidates for the electrochemical CO₂ reduction reaction (eCO₂RR) due to high abundance and tunable catalytic activity of copper. Herein, we report the synthesis and total structure of an alkynyl-protected 21-atom AgCu alloy nanocluster [Ag₁₅Cu₆(C≡CR)₁₈(DPPE)₂]^-, denoted as Ag₁₅Cu₆ (HC≡CR: 3,5-bis(trifluoromethyl)phenylacetylene; DPPE: 1,2-bis(diphenylphosphino)ethane). The single-crystal X-ray diffraction reveals that Ag₁₅Cu₆ consists of an Ag₁₁Cu₄ metal core exhibiting a body-centered cubic (bcc) structure, which is capped by 2 Cu atoms, 2 Ag₂DPPE motifs, and 18 alkynyl ligands. Interestingly, the Ag₁₅Cu₆ cluster exhibits excellent catalytic activity for eCO₂RR with a CO faradaic efficiency (FE_CO) of 91.3% at -0.81 V (vs the reversible hydrogen electrode, RHE), which is much higher than that (FE_CO: 48.5% at -0.89 V vs RHE) of Ag₉Cu₆ with bcc structure. Furthermore, Ag₁₅Cu₆ shows superior stability with no significant decay in the current density and FE_CO during a long-term operation of 145 h. Density functional theory calculations reveal that the de-ligated Ag₁₅Cu₆ cluster can expose more space at the pair of AgCu dual metals as the efficient active sites for CO formation.

An atomically precise Ag18Cu8 nanocluster with rich alkynyl-metal coordination structures and unique SbF6- assembling modes

Elucidating the coordination structures and assembling modes of atomically precise metal nanoclusters (NCs) remains a hot topic as it gives answers to the underlying mechanism of nanomaterials and bulk materials in terms of structure-property relationships. Here we report a novel silver-copper alloy NC featuring rich alkynyl-metal coordination modes and unique SbF₆^- assembling structures. The NC, with the composition of [Ag₁₈Cu₈(dppp)₄(^tBu-C₆H₄CC)₂₂](SbF₆)₄ (dppp = 1,3-bis(diphenylphosphino)-propane), was prepared by a stepwise synthetic approach. Single-crystal X-ray diffraction analysis revealed that such a NC featured a staircase-like Ag₁₈Cu₈ kernel, which was protected by hybrid alkynyl and dppp ligands in diverse coordination structures and multiple environments. The structural analysis also revealed the unique function of SbF₆^- in inducing the assembly of cluster moieties, highlighting the importance of counterions in assembling nanomolecules. The diverse coordination structures of the protective ligands with metal ions and the indispensable roles of counterions in assembling the cluster moieties have also been supported by nuclear magnetic resonance (NMR) and electrospray ionization mass spectrometry (ESI-MS) studies, making it a model system to showcase the uniqueness of atomically precise metal NCs in illustrating the coordination chemistry of nanomaterials and bulk materials at the molecular level.

A bimetallic Ag15Cu12(S-c-C6H11)18(CH3COO)3 nanocluster featuring an irregular Ag12 kernel

Here, we report the synthesis and atomic structure of a Ag₁₅Cu₁₂(SR)₁₈(CH₃COO)₃·(C₆H₁₄) nanocluster (Ag₁₅Cu₁₂ for short, SR denotes cyclohexanethiol), confirmed by single-crystal X-ray diffraction (SC-XRD), electrospray ionization mass spectrometry (ESI-MS), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA). X-ray crystallographic analysis revealed that Ag₁₅Cu₁₂ consisted of an irregular Ag₁₂ core, stabilized by the Ag₃Cu₁₂(SR)₁₈(CH₃COO)₃ shell. The shell consisted of two nearly planar Cu₃(SR)₆ moieties, three monomeric [-SR-Ag-SR-] units and three Cu₂(CH₃COO) staples. Furthermore, time-dependent density functional theory (TD-DFT) simulation was performed to interpret the optical absorption features of Ag₁₅Cu₁₂. Overall, this work will broaden and deepen the understanding of Ag-Cu alloy nanoclusters.

Platonic and Archimedean solids in discrete metal-containing clusters

Metal-containing clusters have attracted increasing attention over the past 2-3 decades. This intense interest can be attributed to the fact that these discrete metal aggregates, whose atomically precise structures are resolved by single-crystal X-ray diffraction (SCXRD), often possess intriguing geometrical features (high symmetry, aesthetically pleasing shapes and architectures) and fascinating physical properties, providing invaluable opportunities for the intersection of different disciplines including chemistry, physics, mathematical geometry and materials science. In this review, we attempt to reinterpret and connect these fascinating clusters from the perspective of Platonic and Archimedean solid characteristics, focusing on highly symmetrical and complex metal-containing (metal = Al, Ti, V, Mo, W, U, Mn, Fe, Co, Ni, Pd, Pt, Cu, Ag, Au, lanthanoids (Ln), and actinoids) high-nuclearity clusters, including metal-oxo/hydroxide/chalcogenide clusters and metal clusters (with metal-metal binding) protected by surface organic ligands, such as thiolate, phosphine, alkynyl, carbonyl and nitrogen/oxygen donor ligands. Furthermore, we present the symmetrical beauty of metal cluster structures and the geometrical similarity of different types of clusters and provide a large number of examples to show how to accurately describe the metal clusters from the perspective of highly symmetrical polyhedra. Finally, knowledge and further insights into the design and synthesis of unknown metal clusters are put forward by summarizing these "star" molecules.

H-bond-induced luminescence enhancement in a Pt1Ag30 nanocluster and its application in methanol detection

Hydrogen bonding is an important type of interaction for constructing nanocluster assemblies. In this study, the role of hydrogen bonding interactions in regulating the fluorescence properties of nanoclusters is investigated. A [Pt₁Ag₃₀(SAdm)₁₄(Bdpm)₄Cl₅]³⁺ (Pt₁Ag₃₀ for short) nanocluster containing hydrogen-accepting ligands is synthesized and its structure is determined. By introducing N-containing ligands into nanoclusters, hydrogen bonding interactions between nanoclusters and polar solvents can be established, which can result in a 35-fold enhancement in the fluorescence intensity (in MeOH vs. in DCM). A series of experiments are designed to demonstrate hydrogen bonding interactions between N atoms in the Pt₁Ag₃₀ cluster and H in the polar solvent and the results show that fluorescence enhancement is derived from the proton-coupled/uncoupled electron transfer between hydrogen bonds. Furthermore, this Pt₁Ag₃₀ is used for the naked-eye detection of MeOH on indicator paper.

Electrochemical CO2 reduction catalyzed by atomically precise alkynyl-protected Au7Ag8, Ag9Cu6, and Au2Ag8Cu5 nanoclusters: probing the effect of multi-metal core on selectivity

We report the first all-alkynyl-protected Au2Ag8Cu5 cluster, which adopts a M@M8@M6 core configuration similar with Au7Ag8/Ag9Cu6 clusters. The three clusters exhibited strong metal core effect toward CO2RR, which was understood by DFT calculations.