Formation of an Alkynyl-Protected Ag112 Silver Nanocluster as Promoted by Chloride Released In Situ from CH2Cl2

By directly reducing alkynyl–silver precursors, we successfully obtained a large alkynyl-protected silver nanocluster, (C₇H₁₇ClN)₃[Ag₁₁₂Cl₆(C≡CAr)₅₁], which is hitherto the largest structurally characterized silver nanocluster in the alkynyl family. The cluster exhibits four concentric core–shell structures (Ag₁₃@Ag₄₂@Ag₄₈@Ag₉), and four types of alkynyl–silver binding modes are observed. Chloride was found to be critical for the stabilization and formation of the silver nanocluster. The release of chloride ions in situ from CH₂Cl₂ solvent has been confirmed by mass spectrometry. This study suggests that the combination of alkynyl and halide ligands will pave a new way for the synthesis of large silver nanoclusters.     

Au57Ag53(C≡CPh)40Br12: A Large Nanocluster with C1 Symmetry

The controlled synthesis and structure determination of a bimetallic nanocluster Au₅₇Ag₅₃(C≡CPh)₄₀Br₁₂ (Au₅₇Ag₅₃) is presented. The metal core has a four‐shell Au₂M₃@Au₃₄@Ag₅₁ @Au₂₀ (M=1/3 Au+2/3 Ag) architecture. In contrast to the previously reported large nanoclusters that have highly symmetric kernel structures, the metal atoms in Au₅₇Ag₅₃ are arranged in an irregular manner with C₁ symmetry. This cluster exhibits excellent thermal stability and is robust under oxidative or basic conditions. The silver precursors play a key role in dictating the structures of the nanoclusters, which suggests the importance of the counteranions used.     

Rhombicuboctahedral Ag100: Four‐Layered Octahedral Silver Nanocluster Adopting the Russian Nesting Doll Model

Precise atomic structure of metal nanoclusters (NCs) is fundamental for elucidating the structure–property relationships and the inherent size‐evolution principles. Reported here is the largest known FCC‐based (FCC=face centered cubic) silver nanocluster, [Ag₁₀₀(SC₆H₃^3,4F₂)₄₈(PPh₃)₈]^?: the first all‐octahedral symmetric nesting Ag nanocluster with a four‐layered Ag₆@Ag₃₈@Ag₄₈S₂₄@Ag₈S₂₄P₈ structure, consistent symmetry elements, and a unique rhombicuboctahedral morphology distinct from theoretical predictions and previously reported FCC‐based Ag clusters. DFT studies revealed extensive interlayer interactions and degenerate frontier orbitals. The FCC‐based Russian nesting doll model constitutes a new platform for the study of the size‐evolution principles of Ag NCs.     

Rhombicuboctahedral Ag100: Four-Layered Octahedral Silver Nanocluster Adopting the Russian Nesting Doll Model

Precise atomic structure of metal nanoclusters (NCs) is fundamental for elucidating the structure–property relationships and the inherent size-evolution principles. Reported here is the largest known FCC-based (FCC=face centered cubic) silver nanocluster, [Ag₁₀₀(SC₆H₃^3,4F₂)₄₈(PPh₃)₈]⁻: the first all-octahedral symmetric nesting Ag nanocluster with a four-layered Ag₆@Ag₃₈@Ag₄₈S₂₄@Ag₈S₂₄P₈ structure, consistent symmetry elements, and a unique rhombicuboctahedral morphology distinct from theoretical predictions and previously reported FCC-based Ag clusters. DFT studies revealed extensive interlayer interactions and degenerate frontier orbitals. The FCC-based Russian nesting doll model constitutes a new platform for the study of the size-evolution principles of Ag NCs.     

A Sodalite‐Type Silver Orthophosphate Cluster in a Globular Silver Nanocluster

The synthesis and structure of a giant 102‐silver‐atom nanocluster (NC) 1 is presented. X‐ray structural analysis reveals that 1 features a multi‐shelled metallic core of Ag₆@Ag₂₄@Ag₆₀@Ag₁₂. An octahedral Ag₆ core is encaged by a truncated octahedral Ag₂₄ shell. The Ag₂₄ shell is composed of a hitherto unknown sodalite‐type silver orthophosphate cluster (SOC) {(Ag₃PO₄)₈}, reminiscent of the Ag₃PO₄ photocatalyst. The SOC is capped by six interstitial sulfur atoms, giving a unique anionic cluster [Ag₆@{(Ag₃PO₄)₈}S₆]^6?, which functions as an intricate polyhedral template with abundant surface O and S atoms guiding the formation of a rare rhombicosidodecahedral Ag₆₀ shell. An array of 6 linear Ag₂ staples further surround this Ag₆₀ shell. [Ag₆@{(Ag₃PO₄)₈}S₆]^6? is an unusual Ag‐based templating anion to induce the assembly of a SOC within silver NC. This finding provides molecular models for bulk Ag₃PO₄, and offers a fresh template strategy for the synthesis of silver NCs with high symmetry.     

A Sodalite-Type Silver Orthophosphate Cluster in a Globular Silver Nanocluster

The synthesis and structure of a giant 102-silver-atom nanocluster (NC) 1 is presented. X-ray structural analysis reveals that 1 features a multi-shelled metallic core of Ag₆@Ag₂₄@Ag₆₀@Ag₁₂. An octahedral Ag₆ core is encaged by a truncated octahedral Ag₂₄ shell. The Ag₂₄ shell is composed of a hitherto unknown sodalite-type silver orthophosphate cluster (SOC) {(Ag₃PO₄)₈}, reminiscent of the Ag₃PO₄ photocatalyst. The SOC is capped by six interstitial sulfur atoms, giving a unique anionic cluster [Ag₆@{(Ag₃PO₄)₈}S₆]⁶⁻, which functions as an intricate polyhedral template with abundant surface O and S atoms guiding the formation of a rare rhombicosidodecahedral Ag₆₀ shell. An array of 6 linear Ag₂ staples further surround this Ag₆₀ shell. [Ag₆@{(Ag₃PO₄)₈}S₆]⁶⁻ is an unusual Ag-based templating anion to induce the assembly of a SOC within silver NC. This finding provides molecular models for bulk Ag₃PO₄, and offers a fresh template strategy for the synthesis of silver NCs with high symmetry.     

Core Modulation of 70‐Nuclei Core‐Shell Silver Nanoclusters

The reaction of {(HNEt₃)₂[Ag₁₀(tBuC₆H₄S)₁₂]}_n, Ag₂O, Na₂MoO₄, and m‐methoxybenzoic acid (Hmbc) in CH₃OH/CH₂Cl₂ led to yellow crystals of [Ag₄S₄ (MoO₄)₅@Ag₆₆] (SD/Ag70b; SD=SunDi) only, while in the presence of DMF, additional dark‐red crystals of [Ag₁₀@ (MoO₄)₇@Ag₆₀] (SD/Ag70a) were obtained. SD/Ag70b consists of five MoO₄^2? ions wrapped by a shell of 66 Ag atoms, while SD/Ag70a contains a rare Ag₁₀ kernel consisting of five tetrahedra sharing faces and edges, surrounded by seven MoO₄^2? ions enclosed in a shell of 60 Ag atoms. The formation of the Ag₁₀ kernel originates from a reduction reaction during the self‐assembly process that involves DMF. This work provides the structural information of a unique Ag₁₀ kernel (five fused Ag₄ tetrahedra) and paves an avenue to trap elusive silver species with hierarchical multi‐shell silver nanocluster assemblies with the help of anion templates.     

Structure of the Ligated Ag60 Nanoparticle [{Cl@Ag12}@Ag48(dppm)12] (where dppm=bis(diphenylphosphino)methane)

A novel bisphosphine ligated Ag₆₀ nanocluster, [{Cl@Ag₁₂}@Ag₄₈(dppm)₁₂], has been dis-covered and characterized by X-ray crystallography. It consists of a central chloride located inside an icosahedral silver core layer, which is further encased by a second shell of 48 silver atoms/ions, which are capped with 12 bis(diphenylphosphino)methane (dppm) ligands. Due to lack of sufficient material the cluster could not be further characterized by other methods. DFT calculations were carried out on the cation [{Cl@Ag₁₂}@Ag₄₈(dppm)₁₂]⁺ to determine if it corresponds to a superatom with a core count of n=58. The DFT optimized structure is in agreement with X-ray ndings, but the low value of the HOMO-LUMO gap does not support superatom stability.     

An Atomically Precise Alkynyl‐Protected PtAg42 Superatom Nanocluster and Its Structural Implications

The synthesis and structure determination of an alkynyl‐protected Pt‐doped Ag superatom nanocluster, [PtAg₄₂(C≡CC₆H₄CH₃)₂₈](SbF₆)₆ (1) , are reported. The metallic core of this cluster can be viewed as a concentric three‐shell Russian doll comprising Pt@Ag₁₂@Ag₃₀, in which the missing icosidodecahedral Ag₃₀ shell and a new structural unit, M₄₃, have been observed. On the surface of 1 , 28 alkynyl groups and 4 SbF₆⁻ anions were found co‐protecting it. The protective role of SbF₆⁻ in nanoclusters is unprecedented. Moreover, of the 28 alkynyl ligands, 12 are connected not only with the outermost Ag₃₀ shell, but also the inner Ag₁₂ shell through the twelve pentagonal faces of the outermost icosidodecahedral Ag₃₀ shell. Overall, by determining the crystal structure of 1 , we discovered the missing icosidodecahedral Ag₃₀ shell and the protective effect of SbF₆⁻ anions and demonstrated a novel M₄₃ structural unit and the unique penetrability of pentagonal faces.     

High‐Nuclearity Silver Thiolate Clusters Constructed with Phosphonates

The n‐butylphosphonate ligand has been employed to construct three new silver(I) thiolate compounds. Single‐crystal X‐ray analysis revealed that complexes 1 and 2 are Ag₄₈ and Ag₅₁ coordination chain polymers, while 3 contains a discrete Ag₄₈ cluster, in which three different kinds of silver(I) thiolate cluster shells enclose three different phosphonate‐functionalized silver(I) cluster cores, respectively. The structures of clusters in 1 – 3 feature three three‐shell arrangements, S@Ag₁₂@(nBuPO₃)₉@Ag₃₆S₂₃, S@Ag₁₁@(nBuPO₃)₇(MoO₄)₂ @Ag₄₀S₂₇ and MoO₄@Ag₁₂@(nBuPO₃)₈S₆ @Ag₃₆S₂₄, respectively.     

Different Silver Nanoparticles in One Crystal: Ag210(iPrPhS)71(Ph3P)5Cl and Ag211(iPrPhS)71(Ph3P)6Cl

Two pure silver nanoparticles (Ag₂₁₀(ⁱPrPhS)₇₁(Ph₃P)₅Cl and Ag₂₁₁(ⁱPrPhS)₇₁(Ph₃P)₆Cl labeled as SD/Ag210 and SD/Ag211 (SD=SunDi), were found to co‐crystallize in forming compound 1 . Single‐crystal X‐ray diffraction (SCXRD) revealed that they differ by only one Ag(PPh₃). Their four‐shell nanoparticles consist of three pure Ag metal shells (Ag₁₉@Ag₅₂@Ag₄₅) shielded by a silver‐organic Ag₈₉(ⁱPrPhS)₇₁Cl[Ag(Ph₃P)]_n outermost shell. The number (n) of Ag(Ph₃P) is five for SD/Ag210 and six for SD/Ag211. The pseudo‐fivefold symmetric Ag nanoparticles exhibit surface plasmon absorption similar to a true metallic state but at the nanoscale. This work exemplifies the important effects of phosphine in stabilizing large silver nanoparticles; and offers a platform to investigate the origin of differences in nanoscale metal materials, even differing by only one metal atom; it also sheds light on the regioselective binding of auxiliary Ph₃P on the surface of silver nanoparticles.     

Beyond Clusters: Supramolecular Networks Self‐Assembled from Nanosized Silver Clusters and Inorganic Anions

Assembly of small clusters into rigid bodies with precise shape and symmetry has been witnessed by the significant advances in cluster‐based metal–organic frameworks (MOFs), however, nanosized silver cluster based MOFs remain largely unexplored. Herein, two anion‐templated silver clusters, CO₃@Ag₂₀ and SO₄@Ag₂₂, were ingeniously incorporated into a 2D sql lattice ( 1 , [CO₃@Ag₂₀(iPrS)₁₀(NO₃)₈(DMF)₂]_n) and an unprecedented 3D two‐fold interpenetrated dia network ( 2 , [SO₄@Ag₂₂(iPrS)₁₂(NO₃)₆ ? 2 NO₃]_n), respectively, under mild solvothermal conditions. Their atomically precise structures were confirmed by single‐crystal X‐ray diffraction analysis and further consolidated by IR spectroscopy, thermogravimetric analysis (TGA), and elemental analysis. Each drum‐like CO₃@Ag₂₀ cluster is extended by twelve NO₃^? ions to form the 2D sql lattice of 1 , whereas each ball‐shaped SO₄@Ag₂₂ cluster with a twisted truncated tetrahedral geometry is pillared by four [Ag₆(NO₃)₃] triangular prisms to form the 3D interpenetrated dia network of 2 . Notably, 2 is the first interpenetrated 3D MOF constructed from silver clusters. These results demonstrate the dual role of the anions, which not only internally act as anion templates to induce the formation of silver thiolate clusters but also externally extend the cluster units into the rigid networks. The photoluminescent and electrochemical properties of 2 are discussed in detail.     

Nestlike Silver(I) Thiolate Clusters with Tunable Emission Color Templated by Heteroanions

Four silver thiolate clusters, [H₃O][(Ag₃S₃)(BF₄)@Ag₂₇(tBuS)₁₈(hfac)₆H₂O] ⋅ H₂O ( 1 ; hfac = hexafluoroacetylacetone), [(Ag₃S₃)(CF₃CO₂)@Ag₃₀(tBuS)₁₆(CF₃CO₂)₉(CH₃CN)₄] ⋅ CF₃CO₂ ⋅ 4 CH₃CN ( 2 ), [(Ag₃S₃)(MoO₄)@Ag₃₀(tBuS)₁₆(CF₃CO₂)₉(CH₃CN)₄] ⋅ 2 CH₃CN ( 3 ), and [(Ag₃S₃)(CrO₄)@Ag₃₀(tBuS)₁₆(CF₃CO₂)₉(CH₃CN)₄] ⋅ 4 CH₃CN ( 4 ), were isolated. They have similar nestlike structures assembled by an [Ag₃S₃]³⁻ template together with one of the BF₄⁻, CF₃CO₂⁻, MoO₄²⁻, or CrO₄²⁻ anions. Interestingly, the solid-state emissions of 2 – 4 are dependent on the templating anions and are tunable from green to orange and then to red by changing the template from CF₃CO₂⁻ to MoO₄²⁻ and to CrO₄²⁻, and this may be correlated to the charge transfer between these templates to metal atoms. This work helps to understand the templating role of heteroanions and the relationship between structure and properties.     

Coexistence of Differently Capped Trigonal Prismatic C2@Ag7 Cages in a Triple Salt of Silver(I) Acetylide

The new silver(I) triple salt 2Ag₂C₂·AgF·9AgNO₃·H₂O was prepared by dissolving Ag₂C₂ in an aqueous solution of AgNO₃ and AgBF₄. Its crystal structure contains two kinds of monocapped trigonal prismatic C₂@Ag₇ cages, with the capping atom occurring on one triangular face or one rectangular face.     

An All‐Alkynyl Protected 74‐Nuclei Silver(I)–Copper(I)‐Oxo Nanocluster: Oxo‐Induced Hierarchical Bimetal Aggregation and Anisotropic Surface Ligand Orientation

The hardness of oxo ions (O^2?) means that coinage‐metal (Cu, Ag, Au) clusters supported by oxo ions (O^2?) are rare. Herein, a novel μ₄‐oxo supported all‐alkynyl‐protected silver(I)–copper(I) nanocluster [Ag_74?xCu_xO₁₂(PhC≡C)₅₀] ( NC‐1 , avg. x=37.9) is characterized. NC‐1 is the highest nuclearity silver–copper heterometallic cluster and contains an unprecedented twelve interstitial μ₄‐oxo ions. The oxo ions originate from the reduction of nitrate ions by NaBH₄. The oxo ions induce the hierarchical aggregation of Cu^I and Ag^I ions in the cluster, forming the unique regioselective distribution of two different metal ions. The anisotropic ligand coverage on the surface is caused by the jigsaw‐puzzle‐like cluster packing incorporating rare intermolecular C?H???metal agostic interactions and solvent molecules. This work not only reveals a new category of high‐nuclearity coinage‐metal clusters but shows the special clustering effect of oxo ions in the assembly of coinage‐metal clusters.     

Silver Thiolate Nano‐sized Molecular Clusters and Their Supramolecular Covalent Frameworks: An Approach Toward Pre‐templated Synthesis

A series of seven new complexes including silver‐thiolate molecular clusters and their covalent supramolecular frameworks have been assembled from the silver carbide precursor Ag₂C₂ using a C₂²⁻ pre‐templated approach. Herein, two prototype clusters Ag₁₄(SR)₆ and CO₃@Ag_m (SR)₁₀ (R=isopropyl, cyclohexyl or tert ‐butyl; m= 18 or 20) are employed to construct cluster‐based metal–organic frameworks of different dimensions. In particular, both new ellipsoidal tetradecanuclear molecular cluster compounds, namely, Ag₁₄(S‐i Pr)₆(CO₂CF₃)₈⋅(DMSO)₆ (two polymorphic forms 1 , 2 ) and [Ag₁₄(S‐Cy)₆(CO₂CF₃)₈(DMSO)₄]⋅(DMSO)₃ ( 3 ), and a cluster‐based metal–organic framework {Ag₃[Ag₁₄(S‐i Pr)₆(CO₂CF₃)₁₁(H₂O)₃CH₃OH]⋅(H₂O)_2.5}_n ( 4 ) have been isolated and structurally characterized. Furthermore, increased acidity of the reaction mixture afforded three carboxylate‐templated cluster based frameworks: a chain‐like compound {[HN(CH₃)₂CO]⋅[CO₃@Ag₁₈(S‐t Bu)₁₀(NO₃)₇(DMF)₄]⋅DMF}_n ( 5 ), as well as two layer‐type compounds, namely, {Ag[CO₃@Ag₂₀(S‐i Pr)₁₀(CO₂CF₃)₉(CO₂HCF₃)(CH₃OH)₂]}_n ( 6 ) and {Ag₂[CO₃@Ag₂₀(S‐Cy)₁₀(CO₂CF₃)₁₀(CO₂HCF₃)₂(H₂O)₂]⋅(H₂O)₃⋅(CH₃OH)₃}_n ( 7 ) exhibiting sql ‐net characteristics. It is demonstrated that the C≡C²⁻ pre‐template, which draws several Ag⁺ ions together to form the C₂@Ag_n entity, plays an indispensable role in the syntheses of these compounds. Furthermore, covalent linkage of these nano‐sized silver thiolate clusters from one‐ to three‐dimensions revealed enormous potential for the future development of silver cluster‐based frameworks.     

Crystal structure of a NIR‐Emitting DNA‐Stabilized Ag16 Nanocluster

DNA has been used as a scaffold to stabilize small, atomically monodisperse silver nanoclusters, which have attracted attention due to their intriguing photophysical properties. Herein, we describe the X‐ray crystal structure of a DNA‐encapsulated, near‐infrared emitting Ag₁₆ nanocluster (DNA–Ag₁₆NC). The asymmetric unit of the crystal contains two DNA–Ag₁₆NCs and the crystal packing between the DNA–Ag₁₆NCs is promoted by several interactions, such as two silver‐mediated base pairs between 3′‐terminal adenines, two phosphate–Ca²⁺–phosphate interactions, and π‐stacking between two neighboring thymines. Each Ag₁₆NC is confined by two DNA decamers that take on a horse‐shoe‐like conformation and is almost fully shielded from the solvent environment. This structural insight will aid in the determination of the structure/photophysical property relationship for this class of emitters and opens up new research opportunities in fluorescence imaging and sensing using noble‐metal clusters.     

Syntheses and Crystal Structures of Copper and Silver Complexes with the Ylide Ph3PCHP(O)PPh2 as Ligand

The reactivity of the hydrolysis product of hexaphenylcarbodiphosphorane, PPh₃CHP(O)Ph₂, towards different soft Lewis acids, such as CuI and Ag[BF₄] are reported. While CuI exclusively binds at the ylidic carbon atom, reaction of the silver cation in CH₂Cl₂ leads to proton abstraction from the solvent to give the cation [PPh₃CH₂P(O)Ph₂]⁺. Surprisingly, Ag⁺ replaces the methyl group of [PPh₃CHMeP(O)Ph₂]⁺ to produce a dimeric complex, in which Ag⁺ is coordinated to C and O forming an eight membered ring. The compounds were characterized by spectroscopic methods and X‐ray diffraction.     

Structural Diversity of Silver Clusters in Double and Triple Salts of Silver Acetylide with Silver Perfluoro-Dicarboxylates

The reactions of Ag₂C₂ and the corresponding silver perfluoro-dicarboxylates result in the formation of three new double and triple salts, Ag₂C₂·3AgO₂CCF₂CF₂CO₂Ag·7H₂O (1), 2Ag₂C₂·6AgO₂CCF₂CF₂CO₂Ag·AgNO₃·12H₂O (2) and Ag₂C₂·4AgO₂CCF₂CF₂CF₂CO₂Ag·17.5H₂O (3), which have been structurally characterized by single crystal X-ray analysis. Their structures contain silver cages of various shapes: crown in 1, pentagonal bipyramid together with monocapped pentagonal bipyramid in 2, and square antiprism in 3, each containing an encapsulated acetylide dianion. Except for the pentagonal bipyramid, the other three silver cages are unprecedented. Compound 2 provides a unique example in which two kinds of silver polyhedra with different numbers of vertices (C₂@Ag₇ and C₂@Ag₈) co-exist in the crystal structure.