New Heteropolytungstates Incorporating Dioxouranium(VI). Derivatives of α-[SiW9O34]10−, α-[AsW9O33]9−, γ-[SiW10O36]8−, and [As4W40O140]28−

Reaction of uranium salts with several lacunary polyoxotungstate anions yields four new heteropolyanion assemblies in which the uranium atoms occupy pentagonal bipyramidal coordination polyhedra. Treatment of A,-[SiW₉O₃₄]^10– with UO₂(NO₃)₂ leads to Na₁₄[Na₂(UO₂)₂(SiW₉O₃₄)₂]38H₂O (1, Monoclinic, P2₁/c, a=16.5719(8) Å, b=14.1689(7) Å, c=21.2528(10) Å, =111.6670(10)°, V=4786.6(4) ų, Z=2) which proves to be isostructural with the analogous derivative of [PW₉O₃₄]^9– reported previously. Solutions of 1 exhibit the 5-line W-NMR spectrum expected for the structure of C _i point symmetry. The salt (NH₄)₁₇[(UO₂)₃(H₂O)₄As₃W₂₆O₉₄]16H₂O (2, Orthorhombic, Pnma, a=40.1747(2) Å, b=18.25840(10) Å, c=18.0817(2) Å, V=13263.4(2) ų, Z=4) was isolated in 64% yield from a reaction of UO₂(NO₃)₂ with B,-[AsW₉O₃₃]^9–. The structure of the anion in 2 has C _s symmetry and contains one -AsW₉O₃₃ and two novel -AsW₈O₃₀ units linked by the UO²⁺ ₂ groups; an additional WO₆ links the two AsW₈ fragments. Spectrophotometric titration of UCl₄ with the sodium salt of [As₄W₄₀O₁₄₀]^28– indicated the formation of a 4:1 U:As₄W₄₀ complex. During attempts to isolate a crystalline product from this reaction the uranium became oxidized and a guanidinium salt of [Na(UO₂)₃(OH)(H₂O)₆As₄W₄₀O₁₄₀(WO)]^18– (3, Orthorhombic, Fdd2, a=54.848(3) Å, b=80.809(4) Å, c=20.2874(2) Å, V=89919(7), Z=16) was isolated. The partially disordered structure of 3 shows the S₂ and adjacent sites of the lacunary As₄W₄₀ anion to be occupied by three UO₅ and one WO₅ polyhedra. A tetrameric assembly of -SiW₁₀ units linked by UO²⁺ ₂ groups occurs in [{M(OH₂)}₄(UO₂)₄(OH)₂(SiW₁₀O₃₆)₄]^22– (lithium salt, M=Na, 4a, tetragonal, P4₂/nmc, a=b=26.5285(2) Å, c=15.0463(2) Å, V=10589.0(2) ų, Z=2; sodium-potassium salt, M=K, 4b, orthorhombic, Fddd, a=24.180(5) Å, b=31.696(6) Å, c=58.012(12) Å, V=44460(15) ų, Z=8). Tungsten-183 NMR spectra show the slow transformation of the expected 5-line (1:1:1:1:1) spectrum of 4a to a new species giving a 6-line spectrum (2:2:2:1:2:1). The latter complex has not been successfully isolated.     

The Unprecedented [S4N2O10]2− Anion in the Molecular Gold Complexes [Au2Br2(S4N2O10)2] and [Au2Cl2(S4N2O10)2](S2O5Cl2)

The reaction of hexachlorophosphazene, P₃N₃Cl₆, with SO₃ and the gold halides AuCl₃ and AuBr₃, respectively, leads to the new cyclic anionic tetramer, [S₄N₂O₁₀]²⁻, which is coordinated to Au³⁺ in the dimeric complexes [Au₂X₂(S₄N₂O₁₀)₂] (X=Cl, Br). The [S₄N₂O₁₀]²⁻ anion can be seen as the condensation product of two sulfate anions, [SO₄]²⁻_, and two amidosulfate anions, [NH₂SO₃]⁻.     

The Oxalato-Titanium-Containing Tungstophosphate(V) Dimers, [Ti8(C2O4)8P2W18O76(H2O)4]18− and [Ti6(C2O4)4P4W32O124]20−

The oxalato-titanium(IV)-containing, dimeric 18-tungsto-2-phosphate [Ti₈(C₂O₄)₈P₂W₁₈O₇₆(H₂O)₄]^18? (1) and the 32-tungsto-4-phosphate [Ti₆(C₂O₄)₄P₄W₃₂O₁₂₄]^20? (2) are formed upon reaction of the oxalato-titanium complex [TiO(C₂O₄)₂]^2? with the trilacunary Keggin precursor [A-α-PW₉O₃₄]^9? and the hexalacunary Wells–Dawson precursor [H₂P₂W₁₂O₄₈]^12?, respectively. Polyanion 1 consists of two {PW₉} units encapsulating eight titanium centers and connected to each other via two Ti–O–Ti bridges, and crystallizes as a mixed potassium-sodium-lithium salt in the triclinic space group $P{\bar{1}}$ . Polyanion 2 comprises two {P₂W₁₆} units containing each two titanium atoms, and the two half-units are connected via two titanium atoms decorated by two oxalate groups each, and crystallizes as a mixed potassium-lithium salt in the rhombohedral space group $R{\bar{3}}c$ . Polyanions 1 and 2 were characterized in the solid state by single-crystal XRD, FT-IR, and TGA, whereas polyanion 2 was also investigated by ³¹P and ¹⁸³W NMR.     

Synthesis and Crystal Structure of Two Decavanadates Cluster Metal Complexes: [Co(H2O)6]2[H2V10O28]·6H2O and (NH4)2[Ca(H2O)7]2[V10O28]

Two new decavanadate metal complexes, [Co(H₂O)₆]₂[H₂V₁₀O₂₈]·6H₂O (1) and (NH₄)₂[Ca(H₂O)₇]₂[V₁₀O₂₈] (2), have been synthesized under hydrothermal condition by using chlorhydric acid as the initiator at 120 °C. The aqueous NaVO₃ solution with an aqueous solution of CoCl₂·6H₂O were used for generating 1 and aqueous CaCl₂·2H₂O and NH₄VO₃ solution were employed for creating 2. Compound 1 consisted of discrete hexa-aqua-cobalt [Co(H₂O)₆]²⁺ cations, [H₂V₁₀O₂₈]⁴⁻ anions and non-coordination water molecules. Compound 2 were composed of hepta-aqua-calcium [Ca(H₂O)₇]²⁺ cations, ammonium NH₄ ⁺ and [V₁₀O₂₈]⁶⁻ anion. For compound 2, the distorted pentagonal bipyramid [Ca(H₂O)₇]²⁺ is uncommon. In the crystal lattice, hydrogen bonds played an important role on connecting cations, anions and non-coordinated water molecules to form the three-dimensional network.     

The 20-Tungsto-4-Tellurate(IV) [H2Te4W20O80]22− and the 15-Tungstotellurate(IV) [NaTeW15O54]13−

The 20-tungsto-4-tellurate(IV) polyanion [H₂Te₄W₂₀O₈₀]^22? (1) has been synthesized and isolated in the form of its hydrated sodium salt Na₂₂[H₂Te₄W₂₀O₈₀]·64H₂O (Na-1). Na-1 has been characterized in the solid state by FTIR and TGA. Single-crystal X-ray diffraction analysis revealed that Na-1 crystallizes in the triclinic space group P ${\bar 1}The 20-tungsto-4-tellurate(IV) polyanion [H₂Te₄W₂₀O₈₀]²²⁻ (1) has been synthesized and isolated in the form of its hydrated sodium salt Na₂₂[H₂Te₄W₂₀O₈₀]·64H₂O (Na-1). Na-1 has been characterized in the solid state by FTIR and TGA. Single-crystal X-ray diffraction analysis revealed that Na-1 crystallizes in the triclinic space group P , with a = 12.741(2) ?, b = 16.842(3) ?, c = 17.197(4) ?, α = 93.961(10)°, β = 107.466(8)°, γ = 108.548(8)°, V = 3281.5(11) ?³ and Z = 1. The polyanion 1 comprises two [HTe₂W₁₀O₄₀]¹¹⁻ fragments, connected through Te−O–W μ₂-oxo bridges, and each containing a pair of face-shared WO₆ octahedra. Furthermore, the 15-tungstotellurate(IV) polyanion [NaTeW₁₅O₅₄]¹³⁻ (2) was synthesized and crystallized as a sodium salt in the orthorhombic space group Pccn, with a = 11.8841(5) ?, b = 20.8934(11) ?, c = 31.801(2) ?, V = 7896.3(7) ?³ and Z = 4. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Dedicated to Professor C. N. R. Rao on the occasion of his 75th birthday     

CRYSTAL STRUCTURE OF (Br(μ-Met)(μ-Gly)(H_2O)_4]_2[Er(μ-Net)_2(H_2O)_4]_2(ClO_4)_(12)

<正> [Er(u-Met)(u-Gly)(H2O)4]2[Er(u-Met)2(HaO)4]2(ClO4)12(NMet=CH3S-(CH2)2CH(NH2)COOH,Gly=NH2CH2COOH), Mr=3194, trilinic, space group P1, a = 12.375(6),b= 14.041(13), c=19.074(13)A,α=80.85(6),β=80.72(6).γ=62.82(6)° ,Z=1,V= 2896A3,Dc=1.83 g/cm3,R=0.091. The carboxyl groups of Met and Gly in the title complex are bonded to Er atoms as bidentate bridging ligands.There are two different cations located at crystallographic symmetry centers in one unit cell.     

Synthesis and structures of mercury and cadmium complexes: [Ph4Sb] 2 + [Hg2I6]2−·Ph2Hg, [Ph4Sb] 2 + [E2I6]2− (E = Hg, Cd), and [Ph4Sb] 2 + [Hg4I10]2−

The reaction of pentaphenylantimony with mercury iodide affords the ionic complex [Ph₄Sb] ₂ ⁺ [Hg₂I₆]^2?·Ph₂Hg (I). The [Ph₄Sb] ₂ ⁺ [Hg₂I₆]^2? (II) and [Ph₄Sb] ₂ ⁺ [Cd₂I₆]^2? (III) complexes are synthesized from tetraphenylantimony iodide and mercury and cadmium iodides. The [Ph₄Sb] ₂ ⁺ [Hg₄I₁₀]^2? complex (IV) is prepared from tetraphenylantimony 2,4-dimethylbenzenesulfonate and mercury iodide. According to the X-ray diffraction data, the Sb atom in the [Ph₄Sb]⁺ cations of complex I has virtually ideal tetrahedral coordination (the CSbC angles are 108.09°–109.64°). In the central square fragment Hg₂I₂ of the [Hg₂I₆]^2? anion, the Hg-I_br bond lengths are 2.825 and 3.075 Å, and the terminal iodine atoms are more strongly bonded to the mercury atoms (Hg-I_term 2.691 and 2.700 Å). The [Cd₂I₆]^2? anion in complex III has a similar structure (the Cd-I_bridg and Cd-I_term distances are 2.865, 2.872 and 2.723, 2.748 Å, respectively). The anions in complex IV are joined by I…Hg (3.651 Å) and I…I (4.058 Å) interactions into an infinite dimeric network.     

Acetate-Functionalized Zirconium-Substituted Tungstogermanate, [Zr4O2(OH)2(CH3COO)2(α-GeW10O37)2]12−

The two acetate-functionalized zirconium(IV)-substituted tungstogermanates, Na₈K₄[Zr₄O₂(OH)₂(CH₃COO)₂(α-GeW₁₀O₃₇)₂] · 33H₂O and Na₈Cs₄[Zr₄O₂(OH)₂(CH₃COO)₂(α-GeW₁₀O₃₇)₂] · 32H₂O, were synthesized by the reaction of ZrOCl₂ with [A-α-GeW₉O₃₄]¹⁰⁻ in pH = 4.8 buffer and their structures were determined by single-crystal X-ray analysis. Both of them contain a centrosymmetric polyanion [Zr₄O₂(OH)₂(CH₃COO)₂(α-GeW₁₀O₃₇)₂]¹²⁻ consisting of two {α-GeW₁₀O₃₇} units sandwiching an inorganic–organic hybrid {Zr₄O₂(OH)₂(CH₃COO)₂} cluster. The polyanion contains a mixing of seven- and eight-coordinate Zr centres. The two compounds were also characterized by elemental analysis, IR spectroscopy, UV–vis and TG–DSC analysis.     

Syntheses and structural determination of binuclear nine-coordinate (NH4)4[SmIII2(Httha)2]·16H2O and 2-D ladder-like binuclear nine-coordinate (NH4)4[SmIII2(dtpa)2]·10H2O

Two rare-earth metal coordination compounds, (NH₄)₄[Sm^III₂(Httha)₂]·16H₂O (1) (H₆ttha?=?triethylenetetramine-N,N,N′,N′′,N′′′,N′′′-hexaacetic acid) and (NH₄)₄[Sm^III₂(dtpa)₂]·10H₂O (2) (H₅dtpa?=?diethylenetriamine-N,N,N′,N′′,N′′-pentaacetic acid), have been synthesized through reflux and characterized by FT-IR spectroscopy, thermal analysis, and single-crystal X-ray diffraction techniques. Sm^III of (NH₄)₄[Sm^III₂(Httha)₂]·16H₂O (1) is nine-coordinate, forming tricapped trigonal prismatic coordination with three amine nitrogens and six oxygens, in which four oxygens are from one ttha and two from the other ttha. (NH₄)₄[Sm^III₂(Httha)₂]·16H₂O (1) crystallizes in the monoclinic crystal system with P2(1)/c space group. The crystal data are: a?=?13.9340(13) Å, b?=?22.890(3) Å, c?=?20.708(2) (14) Å, β?=?99.521(2)°, and V?=?6513.7(13) ų. There are two –NH⁺– groups in the [Sm^III₂(Httha)₂]^4?. The polymeric (NH₄)₄[Sm^III₂(dtpa)₂]·10H₂O (2) also is nine-coordinate with tricapped trigonal prismatic conformation and crystallizes in the triclinic crystal system with P–1 space group. The cell dimensions are: a?=?9.8240(8) Å, b?=?10.0329(9) Å, c?=?13.0941(11) Å, β?=?77.1640(10)°, and V?=?1227.30(18) ų. In (NH₄)₄[Sm^III₂(dtpa)₂]·10H₂O, there are two types of ammonium cations, which connect [Sm^III₂(dtpa)₂]^4? and lattice water through hydrogen bonds, leading to a 2-D ladder-like layer structure.     

[Cu3(μ10-bta)(μ2-C2O4)(H2O)2]n的水热合成与结构表征

有机-无机杂化材料因其在催化、化学吸附、磁性和电子导体等方面具有广泛的应用而成为人们的研究热点[1,2]. 通过过渡金属离子和特殊的有机配体之间的反应, 一系列具有独特结构的配位聚合物已被合成出来. 多齿有机配体可螯合两个或多个金属离子, 这些金属离子之间存在良好的电子交换[3], 可形成一维、二维或三维的配位聚合物. 均苯三甲酸和均苯四甲酸都是良好的桥连多齿配体, Chui等采用均苯三甲酸合成了具有吸附作用的大孔道的[Cu3(tma)2(H2O)]n[4] (tma=benzene-1,3,5-tricarb-oxylate)三维配位聚合物, 并且[Ni(C12H3ON6O2)]3(tma)*H2O[5], [M(tma)2]*12H2O(M=Co,Ni,Zn)[6], Na2[Co(H2O)6(bta)]*4H2O[7] (bta=benzene-1,2,4,5-tetracarboxylate)和[Co(phen)(md)][8] (phen=1,10-phenanthroline, md=benzene-1,3-dicarboxylate)等配位聚合物也先后被合成出来.     

Vanadium(IV)-substituted tungstoantimonate [Sb2W20(VO)2(H2O)4O70]10− : synthesis,crystal structure and electrochemistry

A vanadium(IV)-substituted tungstoantimonate, K₈Na₂[Sb₂W₂₀(VO)₂(H₂O)₄O₇₀]·18.5H₂O (1), has been synthesized in aqueous solution and characterized by IR, UV–Vis, elemental analysis, TG and X-ray single-crystal diffraction analysis. The structure of 1 was composed of two V(IV) ions linked to a [Sb₂W₂₀O₇₀]^14? fragment via V–O(W) bonds; the anions are connected by K⁺ to construct a two-dimensional network complex. The electrochemical behavior of 1 was investigated in buffer solution (pH 2.5) by cyclic voltammetry. In the potential range between ?0.7 and 0.9 V, the compound exhibits successive redox processes of the addenda atoms (W) in a negative potential range, and also redox originating from the substituted atom (V) at a more positive potential. Compound 1 has good electrocatalytic activity towards the reduction of iodate.     

[Bu4N]2[Fe2(μ-S2O3)2(NO)4]: Synthesis,Structure, Redox Properties,and EPR Study

The [n-Bu₄N]₂[Fe₂(-S₂O₃)₂(NO)₄] complex was studied using X-ray diffraction analysis, cyclic voltammetry, and EPR spectroscopy, and its crystal structure was determined. The redox properties of the [Fe₂(-S₂O₃)₂(NO)₄]^2–anion in CH₃CN and CH₂Cl₂solutions were studied. An addition of excess reducer (sodium thiosulfate) to the thiosulfate complex was shown to produce an EPR signal with g= 2.03 typical of the mononuclear iron dinitrosyl complexes. The mechanism for [Fe₂(-S₂O₃)₂(NO)₄]^2–reduction was suggested.     

The preparation and structure of the tetranuclear ruthenium cluster [Ru4(CO)10(μ2-Cl)2(μ3-OEt)2]

The tetranuclear ruthenium cluster [Ru₄(CO)₁₀Cl₂(OEt)₂] has been prepared in low yield by the reaction of [Ru₃(CO)₁₂] with [N(PPh₃)₂]Cl in refluxing EtOH, followed by oxidation with either [NO][BF₄] or Ag[ClO₄]. A single-crystal X-ray analysis of the complex shows that the four metal atoms adopt a planar geometry with one ruthenium bonded by two μ₂-Cl ligands and two μ₃-OEt ligands to a trinuclear fragment. This complex crystallises in the monoclinic space group I2/c, with a 14.458(3), b 22.073(6), c 15.302(4) Å, β 99.54(2)°, Z = 8; 3113 observed data with F > 3σ(F) were refined by blocked full-matrix least squares to R = 0.031, R_w = 0.034.     

Single-molecule magnetism behavior of [Mn12O12(O2CR)16(H2O)4]2− salts

(PPh₄)₂[Mn₁₂O₁₂(O₂CCHCl₂)₁₆(H₂O)₄] (3) has been prepared by the two-electron reduction of [Mn₁₂O₁₂(O₂CCHCl₂)₁₆(H₂O)₄] (2) using iodide. Crystallization from CH₂Cl₂/hexanes yields a mixture of two crystal forms, 3·4CH₂Cl₂·H₂O (3a) and 36CH₂Cl₂ (3b), which are triclinic and monoclinic, respectively. They are both trapped valence 2Mn(II), 6Mn(III), 4Mn(IV). DC magnetization data for dried, unsolvated 3 in 1.80–4.00 K and 10–70 kG ranges were fit to give S=10, D=−0.28 cm⁻¹, g=2.00. Frequency-dependent out-of-phase (χ″_M) signals in AC susceptibility studies on crystalline sample of 3a and 3b combined with DC relaxation decay data were fit to the Arrhenius equation to give an effective energy barrier of U_eff=18.5 and 30.3 K, respectively. Magnetization vs. DC field sweeps on single crystals of 3a and 3b gave hysteresis loops containing steps due to quantum tunneling of magnetization (QTM). The step separations yielded ∣D∣/g values of 0.087 and 0.14 cm⁻¹, and consequently U=20 and 39 K (for g=2) for 3a and 3b, respectively, suggesting that the differences in U_eff are primarily caused by changes to D. This work demonstrates the sensitivity of the magnetic properties of [Mn₁₂]²⁻ single-molecule magnets to subtle differences in their environment.     

K4H2[SiW5Mo6Mn(H2O)O39]·22H2O的晶体结构

合成了一个锰硅钼钨四元取代含氧簇合物,用单晶X射线衍射方法测定了结构,该晶体属于四方晶系,空间群P4/mnc,a=14.119(3),c=12.496(4),V=2490.9(12)3,Mr=2862.70,z=2,Dc=3.817g*cm-3,μ=15.922mm-1,R=0.0462,wR=0.1232.锰硅钼钨阴离子中,中心SiO4四面体在C4轴的两个位置上是无序的.     

Expanding molecular transition metal cubane clusters of the form [M4(μ3)-O)4]12+: syntheses, spectroscopic and structural characterizations of molecules M4(μ3-O)4(O2P(Bn)2)4(O4), M = V(V) and W(V)

Oxidizing the trimer V(3)(μ(3)-O)(O(2))(μ(2)-O(2)P(Bn)(2))(6)(H(2)O) in the presence of excess (t)BuOOH results in V(4)(μ(3)-O)(4)(μ(2)-O(2)P(Bn)(2))(4)(O(4)) and heating W(CO)(6) and bis(benzyl)phosphinic acid in 1:1 EtOH/THF at 120 °C produces W(4)(μ(3)-O)(4)(μ(2)-O(2)P(Bn)(2))(4)(O(4)).     

Syntheses and X-ray Characterization of Novel [M4(H2O)2(XW9O34)2] n− (M=CuII, X=CuII; and M=FeIII, X=FeIII) Polyoxotungstates

Two novel examples of sandwich type heteropolyanions were synthesized and characterized by X-ray crystal structure and elemental analysis as well as infrared spectroscopy. Na₁₃[H₃Cu₄(H₂O)₂(CuW₉O₃₄)₂]39H₂O (1) and Na₉K[Fe₄(H₂O)₂(FeW₉O₃₄)₂]32H₂O (2) were prepared in aqueous solution by reaction of sodium tungstate with Fe^III and Cu^II cations, respectively. 1 crystallizes in the monoclinic space group P2₁/n (a=13.054(3) Å, b=17.729(4) Å, c=20.998(4) Å, =93.50(3)°), while 2 is triclinic, space group P¯1 (a=12.316(2) Å, b=13.716(3) Å, c=14.925(3) Å, =99.36(3)°, =104.21(3)°, =101.55(3)°). Each anion consists of two [XW₉O₃₄] ^n– moieties (X=Fe^III, n=11 (1) and Cu^II, n=12 (2)) which can be described as -B-isomers of the defect Keggin anion. These units are linked via a belt of four Fe^IIIO₆ or Cu^IIO₆ groups. Two transition metal atoms fill their octahedral coordination sphere with one additional water ligand.     

Hydrothermal synthesis and characterization of LaIII and CuII coordination polymers with 5-nitroisophthalic acid (H2Nip), [La2(μ-Nip)(μ-SO4)2(H2O)5] n and {[Cu3(μ-OH)2(μ-Nip)2(μ-H2O)2] · 2H2O} n

3D La^III and 2D Cu^II coordination polymers with 5-nitroisophthalate anions, [La₂(μ-Nip)(μ-SO₄)₂(H₂O)₅] _n (1) and {[Cu₃(μ-OH)₂(μ-Nip)₂(μ-H₂O)₂] ·?2H₂O} _n (2), have been synthesized, characterized and studied by X-ray crystallography. The La atoms have eight–coordinate geometries in distorted square antiprism environments and the Cu atoms have five- and six–coordinate geometries with distorted square pyramidal and octahedral environments. Self-assembly of these compounds in the solid state occurs through coordination and hydrogen bonding.