Unusual ion UO4? formed upon collision induced dissociation of [UO2(NO3)3]?, [UO2(ClO4)3]?, [UO2(CH3COO)3]? ions

The following ions [UO₂(NO₃)₃]⁻, [UO₂(ClO₄)₃]⁻, [UO₂(CH₃COO)₃]⁻ were generated from respective salts (UO₂(NO₃)₂, UO₂(ClO₄)₃, UO₂(CH3COO)2) by laser desorption/ionization (LDI). Collision induced dissociation of the ions has led, among others, to the formation of UO₄ ⁻ ion (m/z 302). The undertaken quantum mechanical calculations showed this ion is most likely to possess square planar geometry as suggested by MP2 results or strongly deformed geometry in between tetrahedral and square planar as indicated by DFT results. Interestingly, geometrical parameters and analysis of electron density suggest it is an U^VI compound, in which oxygen atoms bear unpaired electron and negative charge.     

Multiple-layer heterometallic MnII–AgI coordination polymers constructed from [Ag 2I (CN)3]? and [AgI(CN)2]? units

Two multiple-layer heterometallic Mn^II–Ag^I coordination polymers, {Mn^II(ampyz)(H₂O)[Ag₂^I(CN)₃][Ag^I(CN)₂]·ampyz} _n (1) and {[Mn^II(benzim)₂[Ag^I(CN)₂]₂][(benzim)Ag^I(CN)]·H₂O} _n (2) where ampyz = 2-aminopyrazine and benzim = benzimidazole, have been prepared and structurally characterized. Compound 1 reveals a multiple-layer two-dimensional network with strong hexanuclear argentophilic interactions leading to an infinite three-dimensional framework. Compound 2 has an unprecedented double-layer two-dimensional squared grid-type network with (4,4) topology through Ag^I···Ag^I and π–π interactions between two adjacent squared layers. These double-layer networks of 2 are linked to others by π–π interactions, leading to a three-dimensional framework.     

Crystal structure of [Pd(NH3)4]3[Ir(NO2)6]2·H2O

A single crystal of [Pd(NH₃)₄]₃[Ir(NO₂)₆]₂·H₂O double complex salt is studied by X-ray diffraction. Crystallographic characteristics are as follows: a = 21.0335(5) ?, b = 8.0592(2) ?, c = 21.3452(5) ?, β = 91.254(1)°, V = 3617.43(15) ?³, P2₁/c space group, Z = 4, d _x = 2.714 g/cm³. Single-layer pseudohexagonal packing of complex anions is determined along the [−1 0 1] direction in the structure. Complex cations and crystallization water molecules are located between the mentioned layers.     

[COH(NH2)2]2[Cu(pic)2(ClO4)2]的合成与晶体结构

The title compound was synthesized by reaction of Cu(ClO₄)₂， picolinic acid and carbamide in C₂H₅OH/CH₃CN solution， and characterized by single-crystal X-ray diffraction. It crystallizes in the orthorhombic system， space group Pbca with a=14.0481(8)， b=9.0130(5)， c=18.626(1)?， V=2358.3(2)?³， Z=4， D_x=1.771g·cm^-3， μ=1.235mm^-1 and F(000)=1276. The final R factor is 0.0440 for 1434 observed reflections. The X-ray analysis revealed that the copper(Ⅱ) atom is coordinated by two picolinic ligands in the equatorial plane， while the two oxygen atoms of perchlorate occupy the axial positions of octahedron with lengthened Cu-O distances， resulting in a 4+2 elongated octahedral environment. In the compound， there also exist two protonated carbamide cations for charge balance. CCDC： 195354.     

Synthesis and structure of cobalt complexes [Ph3(n-Pr)P 2+ [CoI4]2? and [Ph3(n-Am)P 2+ [CoI4]2?

Complexes Ph₃(n-Pr)P₂⁺[CoI₄]²⁻ (I) and [Ph₃(n-Am)P]₂⁺ [CoI₄]²⁻ (II) were synthesized by reactions of triphenyl(alkyl)phosphonium iodide with cobalt(II) iodide in acetone. According to the X-ray diffraction data, complexes I and II consist of tetrahedral triphenyl(alkyl)phosphonium cations (for I, P-C is 1.787(4)–1.804(4) ? and CPC is 106.73(18)°–111.4(18)°; for II P-C is 1.786(6)–1.802(6) ? and CPC is 107.6(3)°–111.7(3)°) and [CoI₄]²⁻ anions (Co-I 2.5923(6)–2.6189(6) ?, ICoI 101.86(2)°–113.25(2)° for I; Co-I 2.5899(9)–2.6171(9) 107.01(3)°–110.47(3)° for II).     

EPR study of solid solutions of [Cr(NH3)5Cl]x[Rh(NH3)5Cl]1?x[PdCl4]·nH2O and [Cr(NH3)5Cl]x[Rh(NH3)5Cl]1?x[PtCl4] compounds

In order to determine the features of the structure of double complex salts (DCSs) of [Cr(NH₃)₅Cl]×[MCl₄]·nH₂O, where M = Pd, Pt, n = 0, 1, the DCS solid solutions of palladium and platinum with isostructural DCSs containing the chloropentaammine rhodium cation, [Cr(NH₃)₅Cl] _x [Rh(NH₃)₅Cl]_1−x [MCl₄]·nH₂O, where x = 0.01–0.2, are synthesized and studied by the EPR method. DCSs with the isostructural chloropentaammine rhodium cation are used as a diluter for magneto concentrated systems. It is shown that DCS of platinum and anhydrous DCS of palladium have the identical environment of chromium ions. The EPR spectra of chromium ions for these compounds are described by the following spin Hamiltonian parameters: S = 3/2, g _xx = 1.987, g _yy = 1.987, g _zz = 1.985, D = 1660 Gs, E = 235 Gs. For the palladium complex containing crystalline water, the EPR spectra of chromium ions are described by the parameters: S = 3/2, g _xx = 1.984, g _yy = 1.984, g _zz = 1.984, D = 1060 Gs, E = 350 Gs. A decrease in the crystal field parameters for the aqueous palladium complex is caused by a redistribution of the electron density to the oxygen atom in the second sphere of the chromium ion environment.     

Molecular and crystal structures of [FeCl(HMPA)3(H2O)2]2+(FeCl4) 2? · 3HMPA

IR and single-crystal X-ray diffraction study are carried out for compound, C₃₆H₁₁₂Cl₉Fe₃N₁₈O₈P₆(I). It crystallizes in the orthorhombic space group P2₁2₁2₁ with a = 14.2992(3), b = 21.4351(4), c = 25.5407(5) ?, V = 7828.3(3) ?³, ρ_calcd = 1.553 g/cm³, Z = 4. The FeCl fragment is coordinated with chlorine atom of two water molecules and three HMPA molecules to form a cation, with a distorted octahedral coordinate geometry. In the crystal I, the cation is linked with HMPA by the O-H…O hydrogen bond. The chiral crystal is formed through self-assembly even from achiral molecules.     

Double complex salts [Pd(NH3)4]3[Rh(NO2)6]2, [Pd(NH3)4]3[Rh(NO2)6]2·H2O as promising precursors to prepare Pd-Rh nanoalloys

Two new double complex salts [Pd(NH₃)₄]₃[Rh(NO₂)₆]₂ (I) and [Pd(NH₃)₄]₃[Rh(NO₂)₆]₂·H₂O (II) are synthesized and characterized. The techniques to produce one-phase residues of the salts are developed. The crystallographic data for I: a = 18.915(2) ?, V = 6767.4 ?³, F-43c space group, Z = 8, d _x = 2.548 g/cm³; II: a = 21.160(6) ?, b = 8.085(7) ?, c = 21.363(4) ?, β = 91.71(4)°, V = 3661.1(6) ?³, P2₁/c space group, d _x = 2.357 g/cm³. Thermal properties of the obtained compounds in the hydrogen and helium atmosphere are studied. It is shown that the final product of their decomposition both in the inert and reducing atmosphere is a powder consisting of bimetallic nanosized particles (nanoalloy) of Pd_0.59Rh_0.41 (Fm-3m space group, a = 3.856(2) ?, crystallite size of 8–11 nm).     

Sandwich-type Uranium-Substituted of Bismuthotungstate: Synthesis and Structure Determination of [Na(UO2)2(H2O)4(BiW9O33)2]13?

The sandwich-type [Na(UO₂)₂(H₂O)₄(BiW₉O₃₃)₂]¹³⁻ uranium (VI) has been synthesized by reacting the trivacant species of B-α-[BiW₉O₃₃]⁹⁻ with and investigated by IR and UV–Vis spectroscopy, and elemental analysis. The X-ray single crystal analysis was carried out on Na₁₃[Na(UO₂)₂(H₂O)₄(BiW₉O₃₃)₂] · 33H₂O (I) which crystallizes in the orthorhombic system, space group Pna2₁ with a = 33.8454(19) ?, b = 21.1484(12) ?, c = 13.2403(7) ?, α = 90°, β = 90°, γ = 90°, and Z = 4. The polyanion consists of two lacunary B-α-[BiW₉O₃₃]⁹⁻ groups which sandwich two uranyl cations and one sodium cation. The uranium atoms adopt distorted pentagonal–bipyramidal coordination, achieved by two equatorial bonds to each BiW₉O₃₃ unit and one external water ligand. The coordination of each uranium atom is evident by the shift of ν_as(W–O_b–W) and ν_as(Bi–O) stretching vibrational bonds. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Synthesis and structure of cobalt complexes [Me3EtN] 2+ [CoI4]2? and [Me3BuN] 2+ [CoI4]2?

Complexes [Me₃EtN]₂⁺[CoI₄]²⁻ (I) and [Me₃EtN]₂⁺[CoI₄]²⁻ (II) were synthesized by reacting trimethylalkylammonium iodide with cobalt(II) iodide in acetone. According to X-ray diffraction data, complexes I and II consist of tetrahedral tetraalkylammonium cations (for I, N-C is 1.481(5)–1.590(8) CNC is 107.3(3)°–111.6(3)°; for II, N-C is 1.485(8)–1.506(10) ? and CNC is 106.9(7)°–111.7(5)°) and [CoI₄]²⁻ anions (for I, Co-I is 2.5951(5)–2.6127(5) ? and ICoI is 104.67(2)°–113.23(2)°; for II, Co-I is 2.5914(8)–2.5943(9) ? and ICoI is 107.05(2)°–114.42(5)°).     

Structure Determination of [Au18(SR)14]

Unravelling the atomic structures of small gold clusters is the key to understanding the origin of metallic bonds and the nucleation of clusters from organometallic precursors. Herein we report the X‐ray crystal structure of a charge‐neutral [Au₁₈(SC₆H₁₁)₁₄] cluster. This structure exhibits an unprecedented bi‐octahedral (or hexagonal close packing) Au₉ kernel protected by staple‐like motifs including one tetramer, one dimer, and three monomers. Until the present, the [Au₁₈(SC₆H₁₁)₁₄] cluster is the smallest crystallographically characterized gold cluster protected by thiolates and provides important insight into the structural evolution with size. Theoretical calculations indicate charge transfer from surface to kernel for the HOMO–LUMO transition.     

The Structure and Optical Properties of the [Au18(SR)14] Nanocluster

Decreasing the core size is one of the best ways to study the evolution from Au^I complexes into Au nanoclusters. Toward this goal, we successfully synthesized the [Au₁₈(SC₆H₁₁)₁₄] nanocluster using the [Au₁₈(SG)₁₄] (SG=L ‐glutathione) nanocluster as the starting material to react with cyclohexylthiol, and determined the X‐ray structure of the cyclohexylthiol‐protected [Au₁₈(C₆H₁₁S)₁₄] nanocluster. The [Au₁₈(SR)₁₄] cluster has a Au₉ bi‐octahedral kernel (or inner core). This Au₉ inner core is built by two octahedral Au₆ cores sharing one triangular face. One transitional gold atom is found in the Au₉ core, which can also be considered as part of the Au₄(SR)₅ staple motif. These findings offer new insight in terms of understanding the evolution from [Au^I(SR)] complexes into Au nanoclusters.     

Tuning the Accessibility and Activity of Au25(SR)18 Nanocluster Catalysts through Ligand Engineering

In this work, the effects of thiolate ligands (‐SR, e.g., chain length and functional moiety) on the accessibility and catalytic activity of thiolate‐protected gold nanoclusters (e.g., Au₂₅(SR)₁₈) for 4‐nitrophenol hydrogenation is reported. The data suggest that Au₂₅(SR)₁₈ bearing a shorter alkyl chain shows a better accessibility to the substrates (shown by shorter induction time, t₀) and a higher catalytic activity (shown by higher apparent reaction rate constant, k_app). The functional moiety of the ligands is another determinant factor, which clearly suggests that ligand engineering of Au₂₅(SR)₁₈ would be an efficient platform for fine‐tuning its catalytic properties.     

Ag2Au50(PET)36 Nanocluster: Dimeric Assembly of Au25(PET)18 Enabled by Silver Atoms

The assembly of atomically precise metal nanoclusters offers exciting opportunities to gain fundamental insights into the hierarchical assembly of nanoparticles. However, it is still challenging to control the assembly of individual nanoclusters at a molecular or atomic level. Herein, we report the dimeric assembly of Au₂₅(PET)₁₈ (PET=2‐phenylethanethiol), where two Au₂₅(PET)₁₈ monomers are bridged together by two Ag atoms to form the Ag₂Au₅₀(PET)₃₆ dimer. The Ag₂Au₅₀(PET)₃₆ dimer is a unique mesomer, which has not been found in any other chiral metal nanoclusters. Furthermore, the Ag₂Au₅₀(PET)₃₆ dimer is distinct from the Au₂₅(PET)₁₈ monomer in its optical, electronic, and catalytic properties. This study is expected to provide a feasible strategy to precisely modulate the assembly of metal nanoclusters with controllable structures and properties.     

One‐Pot Synthesis of Phenylmethanethiolate‐Protected Au20(SR)16 and Au24(SR)20 Nanoclusters and Insight into the Kinetic Control

We report two synthetic routes for concurrent formation of phenylmethanethiolate (‐SCH₂Ph)‐protected Au₂₀(SR)₁₆ and Au₂₄(SR)₂₄ nanoclusters in one‐pot by kinetic control. Unlike the previously reported methods for thiolate‐protected gold nanoclusters, which typically involve rapid reduction of the gold precursor by excess NaBH₄ and subsequent size focusing into atomically monodisperse clusters of a specific size, the present work reveals some insight into the kinetic control in gold–thiolate cluster synthesis. We demonstrate that the synthesis of ‐SCH₂Ph‐protected Au₂₀ and Au₂₄ nanoclusters can be obtained through two different, kinetically controlled methods. Specifically, route 1 employs slow addition of a relatively large amount of NaBH₄ under slow stirring of the reaction mixture, while route 2 employs rapid addition of a small amount of NaBH₄ under rapid stirring of the reaction mixture. At first glance, these two methods apparently possess quite different reaction kinetics, but interestingly they give rise to exactly the same product (i.e., the coproduction of Au₂₀(SCH₂Ph)₁₆ and Au₂₄(SCH₂Ph)₂₀ clusters). Our results explicitly demonstrate the complex interplay between the kinetic factors that include the addition speed and amount of NaBH₄ solution as well as the stirring speed of the reaction mixture. Such insight is important for devising synthetic routes for different sized nanoclusters. We also compared the photoluminescence and electrochemical properties of PhCH₂S‐protected Au₂₀ and Au₂₄ nanoclusters with the PhC₂H₄S‐protected counterparts. A surprising 2.5 times photoluminescence enhancement was observed for the PhCH₂S‐capped nanoclusters when compared to the PhC₂H₄S‐capped analogues, thereby indicating a drastic effect of the ligand that is merely one carbon shorter.     

Electrospray ionization mass spectrometry of uniform and mixed monolayer nanoparticles: Au25[S(CH2)2Ph]18 and Au25[S(CH2)2Ph]18-x(SR)x

New approaches to electrospray ionization mass spectrometry (ESI-MS)-with exact compositional assignments-of small (Au25) nanoparticles with uniform and mixed protecting organothiolate monolayers are described. The results expand the scope of analysis and reveal a rich chemistry of ionization behavior. ESI-MS of solutions of phenylethanethiolate monolayer-protected gold clusters (MPCs), Au25(SC2Ph)18, containing alkali metal acetate salts (MOAc) produce spectra in which, for Na+, K+, Rb+, and Cs+ acetates, the dominant species are MAu25(SC2Ph)182+ and M2Au25(SC2Ph)182+. Li+ acetates caused ligand loss. This method was extended to the analysis of Au25 MPCs with mixed monolayers, where thiophenolate (-SPh), hexanethiolate (-SC6), or biotinylated (-S-PEG-biotin) ligands had been introduced by ligand exchange. In negative-mode ESI-MS, no added reagents were needed in order to observe Au25(SC2Ph)18- and to analyze mixed monolayer Au25 MPCs prepared by ligand exchange with 4-mercaptobenzoic acid, HSPhCOOH, which gave spectra through deprotonation of the carboxylic acids. Adducts of tetraoctylammonium (Oct4N+) with -SPhCOO- sites were also observed. Mass spectrometry is the only method that has demonstrated capacity for measuring the exact distribution of ligand-exchange products. The possible origins of the different Au25 core charges (1-, 0, 1+, 2+) observed during electrospray ionization are discussed.     

三苯基膦：转换硫醇保护的纳米粒子成[Au25(PPh3)10(SR)5Cl2]2+

我们在此报道了一种未曾发现的有趣现象：尽管[Au₂₃(SC₆H₁₁)₁₆]⁻、Au₂₄(SC₂H₄Ph)₂₀ (Ph:苯环)、Au₃₆(TBBT)₂₈ (TBBTH:对叔丁基苯硫酚)、Au₃₈(SC₂H₄Ph)₂₄、混合Au_x(SC₂H₄Ph)_y团簇及3 nm的金纳米粒子有不同的组成、结构、尺寸和保护性硫醇配体,但它们在三苯基膦(PPh₃)作用下,均能统一地经由亚稳的[Au₁₁(PPh₃)₈Cl₂]²⁺最终转化为稳定的双二十面体[Au₂₅(PPh₃)₁₀(SR)₅Cl₂]²⁺ (SR:硫醇配体)。换句话说,三苯基膦是这些硫醇保护的纳米粒子的统一转化器。然而,聚乙烯吡咯烷酮(PVP)/柠檬酸盐(Citrate)保护的金纳米粒子和[Ag₂₅(SPhMe₂)₁₈]⁻ (Me:甲基)在同样的条件下,却不能转化为[Au₂₅(PPh₃)₁₀(SR)₅Cl₂]²⁺或[Ag₂₅(PPh₃)₁₀(SR)₅Cl₂]²⁺,暗示了硫醇保护的金纳米粒子具有与三苯基膦反应的独特性能。另外,我们考察了配体对双二十面体[Au₂₅(PPh₃)₁₀(SR)₅Cl₂]²⁺团簇荧光性能的影响。     

Templated Atom‐Precise Galvanic Synthesis and Structure Elucidation of a [Ag24Au(SR)18]− Nanocluster

Synthesis of atom‐precise alloy nanoclusters with uniform composition is challenging when the alloying atoms are similar in size (for example, Ag and Au). A galvanic exchange strategy has been devised to produce a compositionally uniform [Ag₂₄Au(SR)₁₈]^? cluster (SR: thiolate) using a pure [Ag₂₅(SR)₁₈]^? cluster as a template. Conversely, the direct synthesis of Ag₂₄Au cluster leads to a mixture of [Ag_25?xAu_x(SR)₁₈]^?, x=1–8. Mass spectrometry and crystallography of [Ag₂₄Au(SR)₁₈]^? reveal the presence of the Au heteroatom at the Ag₂₅ center, forming Ag₂₄Au. The successful exchange of the central Ag of Ag₂₅ with Au causes perturbations in the Ag₂₅ crystal structure, which are reflected in the absorption, luminescence, and ambient stability of the particle. These properties are compared with those of Ag₂₅ and Ag₂₄Pd clusters with same ligand and structural framework, providing new insights into the modulation of cluster properties with dopants at the single‐atom level.     

The Au25(pMBA)17Diglyme Cluster

A modification of Au₂₅(pMBA)₁₈ that incorporates one diglyme ligand as a direct synthetic product is reported. Notably the expected statistical production of clusters containing other ligand stoichiometries is not observed. This Au₂₅(pMBA)₁₇diglyme product is characterized by electrospray ionization mass spectrometry (ESI-MS) and optical spectroscopy. Thiolate for thiolate ligand exchange proceeds on this cluster, whereas thiolate for diglyme ligand exchange does not.     

Controlled growth of molecularly pure Au25(SR)18 and Au38(SR)24 nanoclusters from the same polydispersed crude product

We report the controlled growth of Au25(SR)18 and Au38 (SR)24 (where R = CH2CH2Ph) nanoclusters of molecular purity via size-focusing from the same crude product that contains a distribution of nanoclusters. In this method, gold salt was first mixed with tetraoctylammonium bromide (TOAB), and then reacted with excess thiol to form Au(I)-SR polymers in THF (as opposed to toluene in previous work), followed by NaBH 4 reduction. The resultant crude product contains polydisperse nanoclusters and was then used as the common starting material for controlled growth of Au25(SR)18 and Au38(SR)24 , respectively. In Route I, Au25(SR)18 nanoclusters of molecular purify were produced from the crude product after 6 h aging at room temperature. In Route II, the crude product was isolated and further subjected to thermal thiol etching in a toluene solution containing excess thiol, and one obtained pure Au38(SR)24 nanoclusters, instead of Au25(SR)18 . This work not only provides a robust and simple method to prepare both Au25(SR)18 and Au38(SR)24 nanoclusters, but also reveals that these two nanoclusters require different environments for the size-focusing growth process.