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A cluster-based luminescent porous metal-organic framework has been constructed through a "cluster linker" approach. The luminescent gold(I) cluster, prefunctionalized with pyrazinyl groups, was used as a cluster linker, similar to an organic linker, to connect silver ions in order to form a 3D framework. 1D channels with 1.1 nm diameter were observed in the framework. The cluster with its intrinsic luminescence was incorporated into a porous framework to give a luminescent bifunctional NbO net. This MOF shows solvatochromic behavior, and the interactions between solvent molecules and silver ions inside the channels account for the changes in absorption and emission spectra., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The phosphorescent silver(I)-gold(I) cluster complex [CAu6Ag2(dppy)6](BF4)4 (N1) selectively stains the nucleolus, with a much lower uptake in the nucleus and cytoplasm, and exhibits excellent photostability. This Ag-Au cluster, which has a photoluminescent lifetime of microseconds, is particularly attractive as a probe in applications of time-gated microscopy. Investigation of the pathway of cellular entry indicated that N1 permeates the outer membrane and nuclear membrane of living cells through an energy-dependent and non-endocytic route within 10 min. High concentrations of N1 in the nucleolus have been quantified by inductively coupled plasma atomic emission spectroscopy (ICP-AES) and transmission electron microscopy coupled with an energy dispersive X-ray analysis (TEM-EDXA), which also helped to elucidate the mechanism of the specific staining. Intracellular selective staining may be correlated with the microenvironment of the nucleolus, which is consistent with experiments conducted at different phases of the cell cycle. These results prove that N1 is a very attractive phosphorescent staining reagent for visualizing the nucleolus of living cells., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Intense solution and solid state phosphorescence was observed on a novel photostable gold(I)-silver(I) cluster with hypercoordinated carbon, [Au(6)Ag(2)(C)(dppy)(6)](BF(4))(4), which has a core structure of a hexagold(I) octahedron with two silver(I) atoms capping on a pair of its faces; the incorporation of silver atoms enhances the rigidity and integrity of the cluster.

Due to the stability issue, It is difficult to prepare a silver nanocluster bearing functional sites, especially at a large scale. We report the synthesis and structure of a stable silver nanocluster bearing multiple surface aldehyde groups [Ag21(Ph2PO2)10(p‐CHOPhC≡C)6]SbF6, which allows for postsynthesis modification such as surface functionalization through aldimine condensation to give homochiral clusters. Remarkably, the preparation of this cluster can be done in ~90 % high yield at gram scale, which facilitates further studies and potential applications. Through DFT calculations and geometric structure analysis, the high stability of this cluster is attributed to the geometric closure and electronic structure. This is the first time that an effective one‐pot method has been developed to synthesize functional silver nanoclusters in high yield. The title cluster will be useful in the development of a variety of cluster‐based materials. [ABSTRACT FROM AUTHOR]

The reduction of alkynyl‐silver and phosphine‐silver precursors with a weak reducing reagent Ph2SiH2 led to the formation of a novel silver nanocluster [Ag93(PPh3)6(C≡CR)50]3+ (R=4‐CH3OC6H4), which is the largest structurally characterized cluster of clusters. This disc‐shaped cluster has a Ag69 kernel consisting of a bicapped hexagonal prismatic Ag15 unit wrapped by six Ino decahedra through edge‐sharing. This is the first time that Ino decahedra are used as a building block to assemble a cluster of clusters. Moreover, the central silver atom has a coordination number of 14, which is the highest in metal nanoclusters. This work provides a diverse metal packing pattern in metal nanoclusters, which is helpful for understanding metal cluster assembling mechanisms. [ABSTRACT FROM AUTHOR]

Anions have been used to regulate the structures and luminescence of heterometallic clusters. Introducing ClO4− into orange‐emissive, butterfly‐like [(C)(Au‐PPhpy2)6Ag4](BF4)6 (1, PPhpy2=bis(2‐pyridyl)phenylphosphine) leads to the formation of red‐emissive [(C)(Au‐PPhpy2)6Ag5(ClO4)3](ClO4)4 (2) with a novel trigonal bipyramidal structure; employing PhCO2− gives yellow‐emissive, hexagram‐like [(C)(Au‐PPhpy2)6Ag6(PhCO2)3](BF4)5 (3). Notably, 1 exhibits weak luminescence in CH2Cl2/CH3OH=1 : 1 (v : v) with a quantum yield (QY) of 0.05, whereas it was dramatically increased to 0.49 and 0.83 for 2 and 3, respectively. Theoretical calculation confirms that the involvement of anions in the electronic structures is responsible for the shifts of emission. The high QYs of 2 and 3 are attributed to the protection provided by ligands and anions. This work demonstrates that anions may serve as an extra designable factor beyond just counterions for functional metal clusters. [ABSTRACT FROM AUTHOR]

Silver nanoclusters containing Ag0 atoms protected by amino acids were synthesized and characterized. Chiral superatomic silver nanoclusters [Ag47L12(C≡CtBu)16]BF4 (L=l‐/d‐valine or l‐/d‐isoleucine) have been prepared by reducing AgC≡CtBu and amino acids (AAs) with NaBH4. Single crystal X‐ray diffraction revealed that these clusters have T symmetry, and the Ag47 metal kernel can be viewed as a tetracapped truncated tetrahedron (Ag17) surrounded with six W‐shaped Ag5 units. The clusters are homochiral as evidenced by CD measurements. As for the strong CD signals, large contributions are found from the occupied Ag s,p states (superatomic D states) near the Fermi level. Electron counting revealed that these clusters are 18‐electron systems, suggesting they are superatomic clusters. The superatomic nature with a 1S21P61D10 configuration was supported by DFT calculations. This work paves the way of taking AAs as facile chiral induction agents for the synthesis of metal nanoclusters. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

We report the total structure determination of a covalently bonded nanocluster polymer [Au7Ag9(dppf)3(CF3CO2)7BF4]n (1). This features a one-dimensional linear chain, consisting of unique molecular building blocks, Au7Ag8(dppf)3(CF3CO2)7 clusters, which are linked together by Ag–O bonds rather than Au–Au interactions or bidentate organic bridges as previously reported. [ABSTRACT FROM AUTHOR]

Abstract: 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. [ABSTRACT FROM AUTHOR]

An intensely luminescent gold(I)-silver(I) cluster [(C)(AuPPhpy2)6Ag6(CF3CO2)3](BF4)5 (PPhpy2=bis(2-pyridyl)phenylphosphine) ( 3) is synthesized by the reaction of [(C)(AuPPhpy2)6Ag4](BF4)6 with AgCF3CO2. All eight faces of the octahedral C@Au6 core in 3 are capped, that is, six faces are capped by silver ions and two by tetrafluoroborates. Cluster 3 is intensely luminescent in solution with a quantum yield of 92 %. Ligation of CF3CO2− ions is vital for the construction and emission properties of 3, as confirmed by DFT calculations. BF4− ions are involved in the protecting sphere of the metal core, as evidenced by 19F NMR data. The participation of phosphines, CF3CO2−, and BF4− ions in the protection of the emissive core and the enhancement of the rigidity of the cluster result in the high emission efficiency. This is the first example of organic ligands and inorganic anions forming a rigid protecting sphere for luminescent coinage-metal clusters. [ABSTRACT FROM AUTHOR]

A red-near-IR dual-emissive nanocluster with the composition [Au10Ag2(2-py−C≡C)3(dppy)6](BF4)5 ( 1; 2-py−C≡C is 2-pyridylethynyl, dppy=2-pyridyldiphenylphosphine) has been synthesized. Single-crystal X-ray structural analysis reveals that 1 has a trigonal bipyramidal Au10Ag2 core that contains a planar Au4(2-py−C≡C)3 unit sandwiched by two Au3Ag(dppy)3 motifs. Cluster 1 shows intense red-NIR dual emission in solution. The visible emission originates from metal-to-ligand charge transfer (MLCT) from silver atoms to phosphine ligands in the Au3Ag(dppy)3 motifs, and the intense NIR emission is associated with the participation of 2-pyridylethynyl in the frontier orbitals of the cluster, which is confirmed by a time-dependent density functional theory (TD-DFT) calculation. [ABSTRACT FROM AUTHOR]

New double salts Ag2C2·6AgO2CCHF2 (1), [HPyCH2OH][Ag9(C2)(CF3CO2)9(HPyCH2OH)(H2O)]·0.5H2O (PyCH2OH=4-(hydroxymethyl)pyridine) (2), Ag2C2·5CF3SO3Ag·2MeCN·2H2O (3) and Ag2C2·8CF3SO3Ag·2EtCN·3H2O (4) have been synthesized by dissolving Ag2C2 in an aqueous solution of the corresponding silver salt followed by the addition of an ancillary ligand. Complex 1 has a three-dimensional structure in which unprecedented basket-like silver cages are inter-connected by difluoroacetate ligands. In 2, centrosymmetric (C2)2@Ag14 double cages with each half taking the shape of a triangulated dodecahedron are linked through additional silver atoms to generate an infinite chain, and unsupported silver(I)–silver(I) interactions exist between neighboring chains. Of the two independent 4-(hydroxymethyl)pyridinium ions in 2, one acts in the O-ligating mode, which is observed for the first time, while the other merely serves to provide charge balance and space-filling. Both 3 and 4 are layer-type structures in which the basic building unit is a distorted monocapped octahedron and monocapped trigonal prism, respectively. [Copyright &y& Elsevier]

Three new polymeric silver cyanide complexes AgCN·AgF·4AgCF3CO2·2CH3CH2CN (3), AgCN·AgCF3CF2CO2 (4) and AgCN·2AgCF3SO3·H2O (5) have been obtained by dissolving AgCN in an aqueous solution of AgX (X=CF3CO2, C2F5CO2 or CF3SO3) and AgBF4, and their layer-type crystal structures determined by X-ray crystallography. In the silver-rich environments, all the co-existing ancillary anions display unusual coordination modes: μ4-O,O,O′,O′-trifluoroacetate and pentafluoropropionate and μ4-η1κO:η1κO′:η1κ2O″-triflate. The cyanide ion functions as a μ3-η1κ2C:η1κN bridge in the construction of an unprecedented chain-like [Ag2(CN)]∞ motif in 4. [Copyright &y& Elsevier]

Surface organic ligands are critical in determining the formation and properties of atomically precise metal nanoclusters. In contrast to the conventionally used thiolate, phosphine and alkynyl ligands, the amine ligand dipyridylamine is applied here as a protecting agent in the synthesis of atomically precise metal nanoclusters. We report two homoleptic amido-protected Ag nanoclusters as examples of all-nitrogen-donor-protected metal nanoclusters: [Ag21(dpa)12]SbF6 (Ag21) and [Ag22(dpa)12](SbF6)2 (Ag22) (dpa = dipyridylamido). Single crystal X-ray structural analysis reveals that both clusters consist of a centered-icosahedron Ag13 core wrapped by 12 dpa ligands. The flexible arrangement of the N donors in dpa facilitates the solvent-triggered reversible interconversion between Ag21 and Ag22 due to their very different solubility. The successful use of dpa in the synthesis of well-defined silver nanoclusters may motivate more studies on metal nanoclusters protected by amido type ligands. Noble metal nanoclusters are commonly protected by thiolate, phosphine, or alkynyl ligands. Here, the authors synthesize two homoleptic amido-protected silver clusters, whose structures interconvert easily with changes of solvent due to the coordination flexibility and diverse binding modes of the nitrogen-donor ligands. [ABSTRACT FROM AUTHOR]

Small anions play a big role in the preparation of an intensely luminescent gold(I)–silver(I) cluster. In their Communication on page 7117 ff. Q.‐M. Wang and co‐workers show that the stepwise addition of silver ions to the gold‐cluster precursor enhances the rigidity of the cluster. The emissive core is fully protected by organic ligands and inorganic anions, which results in high emission efficiency. [ABSTRACT FROM AUTHOR]

Review: 40 refs. [ABSTRACT FROM AUTHOR]

Abstract: A large family of crystalline compounds with silver acetylenediide (Ag2C2) as a component have been synthesized and characterized. In most cases the C2 2− species is enclosed in a silver(I) polyhedron of 6–10 vertices, which may be symbolized as C2@Ag n (n =6–10). In the present review, emphasis is laid on our systematic studies in the controlled generation and supramolecular assembly of C2@Ag n polyhedra to form discrete molecules and higher-dimensional aggregates with the aid of co-existing anions and ancillary ligands. [Copyright &y& Elsevier]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]