首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
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.  相似文献   

2.
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   

3.
Silver chalcogenolate cluster assembled materials (SCAMs) are a category of promising light‐emitting materials the luminescence of which can be modulated by variation of their building blocks (cluster nodes and organic linkers). The transformation of a singly emissive [Ag12(SBut)8(CF3COO)4(bpy)4]n (Ag12bpy, bpy=4,4′‐bipyridine) into a dual‐emissive [(Ag12(SBut)6(CF3COO)6(bpy)3)]n (Ag12bpy‐2) via cluster‐node isomerization, the critical importance of which was highlighted in dictating the photoluminescence properties of SCAMs. Moreover, the newly obtained Ag12bpy‐2 served to construct visual thermochromic Ag12bpy‐2/NH2 by a mixed‐linker synthesis, together with dichromatic core–shell Ag12bpy‐2@Ag12bpy‐NH2‐2 via solvent‐assisted linker exchange. This work provides insight into the significance of metal arrangement on physical properties of nanoclusters.  相似文献   

4.
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   

5.
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   

6.
本文主要描述了由配体2,11-二硫代[3.3]二聚对二甲苯与线性氟代二羧酸银反应制得的三个银配合物的结构。这些配合物的结构因氟代二羧酸银的不同,差别也很大。配体2,11-二硫代[3.3]二聚对二甲苯与氟代丁二酸银反应得到的配合物1是一维链状结构;将银盐换成氟代戊二酸银则获得了三维立体结构的配合物2;若使用氟代己二酸银,则得到了二维多孔的配合物3。在多孔配合物3中,每个孔中容纳了两个客体三甲苯分子,在150℃时这些客体分子可被完全脱除。  相似文献   

7.
(1,4,7‐Tri­thia­cyclo­nonane)silver tri­fluoro­methane­sulfonate crystallizes in a tetrameric form from nitro­methane, to give the title compound, [Ag4(C6H12S3)4](CF3SO3)4·2CH3NO2. The complex cation consists of four [AgL]+ units (L is 1,4,7‐tri­thia­cyclo­nonane), with four Ag—S—Ag bridges forming a cyclic tetramer. The almost planar Ag4S4 ring takes an octagonal form.  相似文献   

8.
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   

9.
Luminescent metal clusters show promise for applications in imaging and sensing. However, promoting emission from metal clusters at room temperature is a challenging task owing to the lack of an efficient approach to suppress the nonradiative decay process in metal cores. We report herein that the addition of a silver atom into a metal interstice of the radarlike thiolated silver cluster [Ag27(StBu)14(S)2(CF3COO)9(DMAc)4]?DMAc ( NC1 , DMAc=dimethylacetamide), which is non‐emissive under ambient conditions, produced another silver cluster [Ag28(AdmS)14(S)2(CF3COO)10(H2O)4] ( NC2 ) that displayed bright green room‐temperature photoluminescence aided by the new ligand 1‐adamantanethiol (AdmSH). The 28th Ag atom, which hardly affects the geometrical and electronic structures of the Ag–S skeleton, triggered the emission of green light as a result of the rigidity of the cluster structure.  相似文献   

10.
Engineering the surface of the metal clusters with the core structure maintained and tuning their luminescence in a wide range is still a challenge in the nanomaterial research. We modified six mono‐pyridyl ligands with different electronic effects (conjugation effect or induction effect) on a superatomic silver cluster [Ag14(C2B10H10S2)6(CH3CN)8] (denoted as Ag14) through in situ site‐specific surface engineering, and obtained the corresponding clusters [Ag14(C2B10H10S2)6(CH3CN)6(L1/L2)2] (denoted as NC‐1, 2, L1/L2 = 4‐acetylpyridine/ 4‐carboxypyridine) and [Ag14(C2B10H10S2)6(L3/L4/L5/L6)8] (denoted as NC‐3, 4, 5, 6, L3/L4/L5/L6 = 4‐phenylpyridine/4‐(1‐naphthyl)pyridine/9‐(4‐pyridine)anthracene/9‐(4‐pyridine)pyrene). Through the modification of the Ag14 cluster, a wide‐range luminescence from blue to red was realized. This work might provide a practical guide for improving the emission performance of metal clusters via surface engineering.  相似文献   

11.
The ditopic ligand 1, 2‐bis(benzimidazol‐1‐ylmethyl)benzene (L1) as well as its silver(I) complexes [Ag2L12(CF3CO2)2] ( 1 ) and [Ag2L12](CF3SO3)2 · (L1) · 2H2O · 0.5C2H5OH ( 2 ) were prepared and structures characterized by X‐ray crystallography. The AgI atoms in 1 are trigonally coordinated by two NBIm atoms from the arms of L1 and by one O atom of the anion CF3CO2, while those in 2 are only linearly ligated by NBIm. Different silver salts of CF3CO2 and CF3SO3 lead to different configurations of the dimeric unit [Ag2L12]2+: chair‐form in ( 1 ) but boat‐form in ( 2 ). The discrete molecules in both 1 and 2 are assembled into network structures through face‐to‐face π · · · π stacking and edge‐to‐face C—H · · · π interactions in the crystalline state, as well as N—H · · · O and C—H · · · O hydrogen bonds. Solution 1H NMR studies showed the formation of one sole species in solution or a rapid equilibrium was established on the NMR time scale at room temperature.  相似文献   

12.
A novel discrete open high‐nuclearity nest‐like silver thiolate cluster complex, [Ag33S3(StBu)16(CF3COO)9(NO3)(CH3CN)2](NO3) ( 1 ), has been isolated with nitrate and S2? anions acting as structure‐directing templates. Its similar nest‐like structure has been assembled into an extended layer [Ag31S3(StBu)16(NO3)9]n ( 2 ) by adjustment of auxiliary ligand. More interestingly, both complexes exhibit temperature‐dependent luminescence of high sensitivity with a large fluorescence enhancement (12‐fold for 1 , 21‐fold for 2 ), which can be easily recognized by the naked‐eye (dramatic red‐shift Δ=104 nm for 1 , larger Δ=113 nm for 2 at 77 K compared to those at 298 K). The correlation between luminescent thermochromism and temperature‐dependent variation of the coordination modes of template NO3? anion, Ag???S and Ag???Ag distances are also elucidated through variable‐temperature single‐crystal X‐ray crystal structure (VT‐SCXRD) analyses.  相似文献   

13.
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   

14.
A general class of C3‐symmetric Ag9 clusters, [Ag9S(tBuC6H4S)6(dpph)3(CF3SO3)] ( 1 ), [Ag9(tBuC6H4S)6(dpph)3(CF3SO3)2] ? CF3SO3 ( 2 ), [Ag9(tBuC6H4S)6(dpph)3(NO3)2] ? NO3 ( 3 ), and [Ag9(tBuC6H4S)7(dpph)3(Mo2O7)0.5]2 ? 2 CF3COO ( 4 ) (dpph=1,6‐bis(diphenylphosphino)hexane), with a twisted trigonal‐prism geometry was isolated by the reaction of polymeric {(HNEt3)2[Ag10(tBuC6H4S)12]}n, 1,6‐bis(diphenylphosphino)hexane, and various silver salts under solvothermal conditions. The structures consist of discrete clusters constructed from a girdling Ag9 twisted trigonal prism with the top and bottom trigonal faces capped by diverse anions (i.e., S2? and CF3SO3? for compound 1 , 2×CF3SO3? for compound 2 , 2×NO3? for compound 3 , and tBuC6H4S? and Mo2O72? for compound 4 ). This trigonal prism is bisected by another shrunken Ag3 trigon at its waist position. Interestingly, two inversion‐related Ag9 trigonal‐prismatic clusters are dimerized by the Mo2O72? ion in compound 4 . The twist is amplified by the bulkier thiolate, which also introduces high steric‐hindrance for the capping ligand, that is, the longer dpph ligand. Four more silver–sulfur clusters (namely, compounds 5 – 8 ) with their nuclearity ranging from 6–10 were solely characterized by single‐crystal X‐ray diffraction to verify the above‐described synergetic effect of mixed ligands in the construction of Ag9 twisted trigonal prisms. Surprisingly, only cluster 1 emits yellow luminescence at λ=584 nm at room temperature, which may be attributed to a charge transfer from the S 3p orbital to the Ag 5s orbital, or mixed with metal‐centered (MC) d10→d9s1 transitions. Upon cooling from 300 to 80 K, the emission intensity was enhanced along with a hypsochromic shift. The good linear relationship between the maximum emission intensity and the temperature for compound 1 in the range of 180–300 K indicates that this is a promising molecular luminescent thermometer. Furthermore, cyclic voltammetric studies indicated that the diffusion‐ and surface‐controlled redox processes were determined for compounds 1 and 3 as well as compound 4 , respectively.  相似文献   

15.
The bifunctional pyridine‐2,3‐dicarboxylic acid (H2pdc) ligand has one N atom and four O atoms, which could bind more than one AgI centre with diverse binding modes. A novel infinite one‐dimensional AgI coordination polymer, namely catena‐poly[[silver(I)‐(μ2‐pyridine‐2,3‐dicarboxylato‐κ2N :O 3)‐silver(I)‐tris(μ2‐5‐methyl‐1,3,4‐thiodiazol‐2‐amine‐κ2N :N ′)] monohydrate ethanol monosolvate], {[Ag2(C7H3NO4)(C3H5N3S)3]·H2O·C2H5OH}n , has been synthesized using H2pdc and 5‐methyl‐1,3,4‐thiadiazol‐2‐amine (tda), and characterized by single‐crystal X‐ray diffraction. One AgI atom is located in a four‐coordinated AgN4 tetrahedral geometry and the other AgI atom is in a tetrahedral AgN3O geometry. A dinuclear AgI cluster formed by three tda ligands with a paddelwheel configuration is bridged by the dianionic pdc2− ligand into a one‐dimensional coordination polymer. Interchain N—H…O hydrogen bonds extend the one‐dimensional chains into an undulating two‐dimensional sheet. The sheets are further packed into a three‐dimensional supramolecular framework by interchain N—H…O hydrogen bonds.  相似文献   

16.
The title compound, {[Ag2(C4H4N2)3](CF3SO3)2·2H2O}n, is a polymeric pyrazine–silver(I) complex. Each AgI ion is three‐coordinated by N atoms of three different pyrazine ligands, forming a T‐shaped coordination configuration. In the crystal structure, uncoordinated water mol­ecules are linked to tri­fluoro­methane­sulfonate anions through intermolecular O—H⋯O hydrogen bonds. There are weaker Ag⋯O interactions involving the water and sulfonate O atoms.  相似文献   

17.
As part of a study on the effect of different counter‐anions on the self‐assembly of coordination complexes, a new dinuclear AgI complex, [Ag2(C14H12N4)2](CF3SO3)2, with the 3‐[3‐(2‐pyridyl)pyrazol‐1‐ylmethyl]pyridine (L) ligand was obtained through the reaction of L with AgCF3SO3. In this complex, each AgI center in the centrosymmetric dinuclear complex cation is coordinated by two pyridine and one pyrazole N‐atom donor of two inversion‐related L ligands in a trigonal planar geometry. This forms a unique box‐like cyclic dimer with an intramolecular nonbonding Ag...Ag separation of 6.379 (7) Å. Weak Ag...CF3SO3 and C—H...X (X = O and F) hydrogen‐bonding interactions, together with π–π stacking interactions, link the complex cations along the [001] and [10] directions, respectively, generating two different one‐dimensional chains and then an overall two‐dimensional network of the complex running parallel to the (110) plane. Comparison of the structural differences with previous findings suggests that the presence of different counter‐anions plays an important role in the construction of such supramolecular frameworks.  相似文献   

18.
Compound [Ag42S5(StBu)25(CF3COO)4(CO3)](CO3)0.5?CH2Cl2?4CH3OH?9DMF ( 1 ) has been obtained and well defined. It consists of a multi‐shell structure involving two Ag centres, one Ag5S5 pentagram, two Ag5S5 pentagons and one Ag25S15 shell. Compound 1 has been characterized by XPS, FT‐IR, PXRD, TGA, NMR, MS, UV/Vis spectrum, TEM and cyclic voltammetry. Temperature‐sensitive luminescent property of 1 has also been investigated.  相似文献   

19.
The synthesis and characterization of the first supramolecular aggregates incorporating the organometallic cyclo‐P3 ligand complexes [CpRMo(CO)23‐P3)] (CpR=Cp (C5H5; 1a ), Cp* (C5(CH3)5; 1b )) as linking units is described. The reaction of the Cp derivative 1a with AgX (X=CF3SO3, Al{OC(CF3)3}4) yields the one‐dimensional (1D) coordination polymers [Ag{CpMo(CO)2(μ,η311‐P3)}2]n[Al{OC(CF3)3}4]n ( 2 ) and [Ag{CpMo(CO)2(μ,η311‐P3)}3]n[X]n (X=CF3SO3 ( 3a ), Al{OC(CF3)3}4 ( 3b )). The solid‐state structures of these polymers were revealed by X‐ray crystallography and shown to comprise polycationic chains well‐separated from the weakly coordinating anions. If AgCF3SO3 is used, polymer 3a is obtained regardless of reactant stoichiometry whereas in the case of Ag[Al{OC(CF3)3}4], reactant stoichiometry plays a decisive role in determining the structure and composition of the resulting product. Moreover, polymers 3a, b are the first examples of homoleptic silver complexes in which AgI centers are found octahedrally coordinated to six phosphorus atoms. The Cp* derivative 1b reacts with Ag[Al{OC(CF3)3}4] to yield the 1D polymer [Ag{Cp*Mo(CO)2(μ,η321‐P3)}2]n[Al{OC(CF3)3}4]n ( 4 ), the crystal structure of which differs from that of polymer 2 in the coordination mode of the cyclo‐P3 ligands: in 2 , the Ag+ cations are bridged by the cyclo‐P3 ligands in a η11 (edge bridging) fashion whereas in 4 , they are bridged exclusively in a η21 mode (face bridging). Thus, one third of the phosphorus atoms in 2 are not coordinated to silver while in 4 , all phosphorus atoms are engaged in coordination with silver. Comprehensive spectroscopic and analytical measurements revealed that the polymers 2 , 3a , b , and 4 depolymerize extensively upon dissolution and display dynamic behavior in solution, as evidenced in particular by variable temperature 31P NMR spectroscopy. Solid‐state 31P magic angle spinning (MAS) NMR measurements, performed on the polymers 2 , 3b , and 4 , demonstrated that the polymers 2 and 3b also display dynamic behavior in the solid state at room temperature. The X‐ray crystallographic characterisation of 1b is also reported.  相似文献   

20.
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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号