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1.
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(SC6H33,4F2)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.  相似文献   

2.
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.  相似文献   

3.
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.  相似文献   

4.
The change in the valence state of nanocluster can induce remarkable changes in the properties and structure. However, achieving the valence state changes in nanoclusters is still a challenge. In this work, we use Cu2+ as dopant to “oxidize” [Ag62S12(SBut)32]2+ (4 free electrons) to obtain the new nanocluster: [Ag62−xCuxS12(SBut)32]4+ with 2 free electrons. As revealed by its structure, the [Ag62−xCuxS12(SBut)32]4+ (x=10∼21) has a similar structure to that of [Ag62S12(SBut)32]2+ precursor and all the Cu atoms occupy the surface site of nanocluster. It′s worth noting that with the Cu atoms doping, the [Ag62−xCuxS12(SBut)32]4+ nanocluster is more stable than [Ag62S12(SBut)32]2+ at higher temperature and in electrochemical cycle. This result has laid a foundation for the subsequent application and exploration. Overall, this work reveals crystals structure of a new Ag−Cu nanocluster and offers a new insight into the electron reduction/oxidation of nanocluster.  相似文献   

5.
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 MoO42? 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 MoO42? 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.  相似文献   

6.
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.  相似文献   

7.
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.  相似文献   

8.
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.  相似文献   

9.
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.  相似文献   

10.
《化学:亚洲杂志》2017,12(22):2904-2907
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.  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
《化学:亚洲杂志》2017,12(20):2763-2769
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@Agm (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@Agn 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.  相似文献   

14.
The synergistic Ag+/X2 system (X=Cl, Br, I) is a very strong, but ill‐defined oxidant—more powerful than X2 or Ag+ alone. Intermediates for its action may include [Agm(X2)n]m+ complexes. Here, we report on an unexpectedly variable coordination chemistry of diiodine towards this direction: ( A )Ag‐I2‐Ag( A ), [Ag2(I2)4]2+( A ?)2 and [Ag2(I2)6]2+( A ?)2?(I2)x≈0.65 form by reaction of Ag( A ) ( A =Al(ORF)4; RF=C(CF3)3) with diiodine (single crystal/powder XRD, Raman spectra and quantum‐mechanical calculations). The molecular ( A )Ag‐I2‐Ag( A ) is ideally set up to act as a 2 e? oxidant with stoichiometric formation of 2 AgI and 2 A ?. Preliminary reactivity tests proved this ( A )Ag‐I2‐Ag( A ) starting material to oxidize n‐C5H12, C3H8, CH2Cl2, P4 or S8 at room temperature. A rough estimate of its electron affinity places it amongst very strong oxidizers like MF6 (M=4d metals). This suggests that ( A )Ag‐I2‐Ag( A ) will serve as an easily in bulk accessible, well‐defined, and very potent oxidant with multiple applications.  相似文献   

15.
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.  相似文献   

16.
The [AuxAg16-x(SAdm)8(Dppe)2] nanocluster with aggregation-induced emission (AIE) was synthesized from a non-fluorescent [Au9Ag12(SAdm)4(Dppm)6Cl6](SbF6)3 nanocluster via a ligand-exchange engineering (Dppe=1,2-Bis(diphenylphosphino)ethane, Dppm=Bis(diphenylphosphino)methane, HSAdm=1-Adamantanethiol). The nanocluster has a Au-doped icosahedral AuxAg13-x core, capped by two Ag(SR)3, one Ag(SR)2 and two Dppe ligands. By changing the achiral Dppe ligand into a chiral dbpb ligand ((2S,3S)-(-)-Bis(diphenylphosphino)butane or (2R,3R)-(+)-2,3-Bis(diphenylphosphino)butane), chiral nanoclusters are obtained. ESI-MS and UV-vis spectroscopy were performed to track the reaction. This work provides guidance for the construction of new clusters by etching clusters with multidentate phosphine ligands.  相似文献   

17.
Building on previous single crystal X‐ray structure determinations for the group 1 salts of complex thiosulfate/univalent coinage metal anions previously defined for (NH4)9AgCl2(S2O3)4, NaAgS2O3·H2O and Na4[Cu(NH3)4][Cu(S2O3)2]·NH3, a wide variety of similar salts, of the form , M1 = group 1 metal cation, M2 = univalent coinage metal cation (Cu, Ag), (X = univalent anion), most previously known, but some not, have been isolated and subjected to similar determinations. These have defined further members of the isotypic, tetragonal series, for M1 = NH4, M2 = Cu, Ag, X = NO3, Cl, Br, I, together with the K/Cu/NO3 complex, all containing the complex anion [M2(SSO3)4]7? with M2 in an environment of symmetry, Cu, Ag‐S typically ca. 2.37, 2.58Å, with quasi‐tetrahedral S‐M‐S angular environments. Further salts of the form , n = 1‐3, have also been defined: For n = 3, M2 = Cu, M1/x = K/2.25 or 1 5/6, NH4/6, (and also for the (NH4)4Na/4H2O·MeOH adduct) the arrays take the form with distorted trigonal planar CuS3 coordination environments, Cu‐S distances being typically 2.21Å, S‐Cu‐S ranging between 105.31(4)–129.77(4)°; the silver counterparts take the form for M1 = K, NH4. For n = 2, adducts have only been defined for M2 = Ag, the anions of the M1 = Na, K adducts being dimeric and polymeric respectively: Na6[(O3SS)2Ag(μ‐SSO3)2Ag(SSO3)]·3H2O, K3[Ag(μ‐SSO3)2](∞|∞)·H2O; a polymeric copper(I) counterpart of the latter is found in Na5Cu(NO3)2(S2O3)2 ≡ 2NaNO3·Na3[Cu(μ‐SSO3)2](∞|∞). For n = 1, NaAgS2O3, the an‐ and mono‐ hydrates, exhibit a two‐dimensional polymeric complex anion in both forms but with different contributing motifs. (NH4)13Ag3(S2O3)8·2H2O takes the form (NH4)13[{(O3SS)3Ag(μ‐SSO3)}2Ag], a linearly coordinated central silver atom linking a pair of peripheral [Ag(SSO3)4]7? entities. In Na6[(O3SS)Ag(μ‐SSO3)2Ag(SSO3)]·3H2O, the binuclear anions present as Ag2S4 sheets, the associated oxygen atoms being disposed to one side, thus sandwiching layers of sodium ions; the remarkable complex Na5[Ag3(S2O3)4](∞|∞)·H2O is a variant, in which one sodium atom is transformed into silver, linking the binuclear species into a one‐dimensional polymer. In (NH4)8[Cu2(S2O3)5]·2H2O a binuclear anion of the form [(O3SS)2Cu(μ‐S.SO3)Cu(SSO3)2]8? is found; the complex (NH4)11Cu(S2O3)6 is 2(NH4)2(S2O3)·(NH4)7[Cu(SSO3)4]. A novel new hydrate of sodium thiosulfate is described, 4Na4S2O3·5H2O, largely describable as sheets of the salt, shrouded in water molecules to either side, together with a redetermination of the structure of 3K2S2O3·H2O.  相似文献   

18.
An assembly strategy for metal nanoclusters using electrostatic interactions with weak interactions, such as C?H???π and π???π interactions in which cationic [Ag26Au(2‐EBT)18(PPh3)6]+ and anionic [Ag24Au(2‐EBT)18]? nanoclusters gather and assemble in an unusual alternating array stacking structure is presented. [Ag26Au(2‐EBT)18(PPh3)6]+ [Ag24Au(2‐EBT)18]? is a new compound type, a double nanocluster ion compound (DNIC). A single nanocluster ion compound (SNIC) [PPh4]+ [Ag24Au(2‐EBT)18]? was also synthesized, having a k‐vector‐differential crystallographic arrangement. [PPh4]+ [Ag24Au(2,4‐DMBT)18]? adopts a different assembly mode from both [Ag26Au(2‐EBT)18(PPh3)6]+ [Ag24Au(2‐EBT)18]? and [PPh4]+ [Ag24Au(2‐EBT)18]?. Thus, the striking packing differences of [Ag26Au(2‐EBT)18(PPh3)6]+ [Ag24Au(2‐EBT)18]?, [PPh4]+ [Ag24Au(2‐EBT)18]? and the existing [PPh4]+ [Ag24Au(2,4‐DMBT)18]? from each other indicate the notable influence of ligands and counterions on the self‐assembly of nanoclusters.  相似文献   

19.
A novel Ag doped Au44(C10H9)28 nanocluster (C10H10=1-ethynyl-2,4-dimethylbenzene) was synthesized, that is, Ag4+xAu40-x(C10H9)28 (x≤6), where four Ag positions located in the surface staple of the cluster have been determined, while six Au/Ag co-occupying positions have been found in the metal core of the cluster. The electronic configuration of Au44(C10H9)28 cluster is significantly disturbed by doping Ag atoms, hence promoting the electron transport capability. For the two-electron conversion reaction of CO2 to CO in electrochemical reduction of CO2, Ag doped Ag4+xAu40-x(C10H9)28 catalyst exhibited higher effective activity and long-term stability than its counterpart Au44(C10H9)28 catalyst.  相似文献   

20.
Herein we report a crystal structure of [Au0.5Ag0.5@Ag20{S2P(OiPr)2}12](PF6) [Cl@Ag8{S2P(OiPr)2}6](PF6) (1), which compositions were supported by positive-mode electrospray ionization mass spectrometry. The structural elucidation indicates that the encapsulated atom of an Ag13 the entered icosahedron can be replaced by a gold atom. Surprisingly, the capping Ag atoms on the surface of an icosahedron in 1 reveal a different arrangement from the previously reported [Ag21{S2P(OiPr)2}12](PF6) of C3 symmetry. Besides, the preference for the central silver atom being oxidized by Au(I) is rationalized by the DFT calculations on three different computed [AuAg20{S2PH2}12]+ models having C1, C3, and T symmetry, respectively.  相似文献   

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