A Novel Polyoxovanadium Cluster Shell: β‐As8V14O42

The hydrothermal reaction of VOSO₄, As₂O₅, piperazine and H₂O produces [H₂N(CH₂)₄NH₂]₄[β‐As₈V₁₄O₄₂(SO₄)]·2HSO₄ ( 1 ), which is the first arsenic‐vanadium cluster containing a spherical β‐As₈V₁₄O₄₂ shell. The structure of this compound was characterized by single crystal X‐ray diffraction, elemental analysis, TG, and IR spectrum. Crystal data for 1 : Orthorhombic, Cmcm, a = 15.369(1) Å, b = 16.404(1) Å, c = 25.772(1) Å, V = 6497.4(9) ų, Z = 4.     

Controlling Nucleation and Crystal Growth of a Distinct Polyoxovanadate Cluster: An In Situ Energy Dispersive X‐ray Diffraction Study under Solvothermal Conditions

The formation of the antimonato polyoxovanadates [V₁₄Sb₈(C₆H₁₅N₃)₄O₄₂(H₂O)] ? 4H₂O ( 1 ), (C₆H₁₇N₃)₂[V₁₅Sb₆(C₆H₁₅N₃)₂O₄₂(H₂O)] ? 2.5H₂O ( 2 ), {C₆H₁₅N₃}₄[V₁₆Sb₄O₄₂] 2H₂O ( 3 ) (C₆H₁₅N₃=1‐(2‐aminoethyl)piperazine, AEP) has been studied under solvothermal conditions by using in situ energy dispersive X‐ray diffraction (EDRXD). The syntheses were performed with an identical ratio for Sb₂O₃ and NH₄VO₃. If the reactions slurries are not stirred during the solvothermal reaction and by applying 70–75 % amine concentration, the products contain all three compounds, whereas 3 is observed at 80 %. Under stirring conditions, variation of the concentration of AEP led to crystallization of the three different compounds at distinct concentrations, that is, 1 is formed at 75 %, 1 and 2 between 75 and 80 % and 3 at 80 %. At an amine concentration of 77.5 %, first reflections of 2 occurred and at later stages, compound 1 started to crystallize. The sample with the lowest number of V^IV species was formed at the lowest amine concentration, whereas crystallization of 3 required the highest concentration. The formation of the compounds occurred without crystalline intermediates and/or precursors. With increasing reaction temperature, the incubation time was significantly reduced.     

The Missing Link in Low Nuclearity Pure Polyoxovanadate Clusters: Preliminary Synthesis and Structural Analysis of a New {V16} Cluster and Related Products

Two new metastable polyoxovanadate-based cluster compounds have been isolated and crystallographically characterized with nuclearities of {V₁₆} (1) and {V₁₈} (2). The {V₁₆} cluster represents a new framework type and incorporates two protons into the cluster framework whereas the {V₁₈} framework has been previously characterised, and the oxidation states of the {V₁₈} cluster can be assigned as {V^IV ₁₅V^V ₃}. Compound K₁₀[H₂V₁₆O₃₈]13H₂O (1) crystallizes in the monoclinic space group P2₁/c, a=12.12820(10), b=38.2302(3), c=12.35400(10) Å, =115.0470(10)°, V=5189.43(7) ų, D _c=2.624 gcm^–3. 10086 unique reflection and 702 refined parameters were used in structure refinement. R1=0.039, R2=0.109 (all data). From the same preparation the new compound K₁₁[V₁₈O₄₂(SO₄)]20H₂O (2) was also isolated and crystallographically characterized. Compound 2 crystallizes in the monoclinic space group P2₁/n, a=12.7854(3), b=20.2812(5), c=13.2386(4) Å, =115.3400(10)°, V=3102.53(14) ų, D _c=2.650 gcm^–3. 7115 unique reflections and 462 refined parameters were used in structure refinement. R1=0.046, R2=0.121 (all data).     

含有两个簇阴离子[As_8V_(14)O_(42)(SO_4)]~(6-)的金属-氧簇合物(H_2en)_6[As_8V_(14)O_(42)(SO_4)]_28H_2O的水热合成与晶体结构

合成了一种新的砷-钒-氧簇合物(H2en)6[As8V14O42(SO4)]28H2O(en为乙二胺),用元素分析、IR和TG-DTA等手段进行了表征,并用X射线衍射法测定了晶体结构。结果表明, 该晶体属单斜晶系,P21/c空间群,晶胞参数a = 20.9235(4),b = 11.9382(2),c = 43.5783(6) 牛琤 = 102.13,V = 10642.1(3) ?,Z = 4,Mr = 4678.01,Dc = 2.920 g/cm3,F(000) = 8944,m = 7.437 mm-1,R = 0.0735,wR = 0.1361。结构测定表明,结构中2个簇阴离子{[As8V14O42(SO4)]6-}与有机铵阳离子[H2en]2+之间靠静电作用相结合,同时与H2O通过氢键构成无限的三维骨架结构。     

Ein neues Syntheseverfahren für Vanadiumbronzen. Die Kristallstruktur von β?Ag0,33V2O5. Verfeinerung der Kristallstruktur von ϵ?Cu0,76V2O5

A Novel Means of Synthesis for Vanadium Bronzes. Crystal Structure of β? Ag_0.33V₂O₅. Refinement of the Crystal Structure of ?? Cu_0.76V₂O₅ Ag_0.33V₂O₅ and Cu_0.76V₂O₅ were obtained by heating equimolar mixtures of AgI + V₂O₅ (700°C) and CuI + V₂O₅ (525°C), respectively, in sealed quartz glass ampoules. In each case, one of the well-formed crystals served for an X-ray structure analysis. Ag_0.33V₂O₅ has the structure known of the β phase of the vanadium bronzes, i. e. layers of edge-sharing, distorted VO₆ octahedra are liked by certain common octahedron vertices, the Ag atoms randomly occupy two positions with occupation probabilities of 0.5. Cu_0.76V₂O₅ has the previously determined structure of the ? phase, however, its space group is not Cm but C2/m.     

Hydrothermal Synthesis and Structure of a Novel Two-dimensional Complex:[Ni_(0.5)(H_2O)_(1.5){Ni(en)_2}_3V_(18)O_(42)(Cl)]3.5H_2O

1 INTRODUCTION The crystal engineering of inorganic-organic hybrid materials has generated significant interest in their new structural architectures and potential ap- plications in the fields of photochemistry, catalysis, electromagnetism and sorption[1…     

Expansion of Germanato‐Polyoxovanadate Cluster Cores: Solvothermal Syntheses and Selected Properties of (trenH2)2[{M(tren)}4V15Ge6O48(H2O)] (M = Co and Zn)

Two germanato‐polyoxovanadates with the {V₁₅Ge₆O₄₈} cluster core are extended by covalent bonds to four transition metal amine complexes [M(tren)]²⁺ (M = Co and Zn, tren = tris(2‐aminoethyl)amine). The complexes have bonds to terminal atoms of the Ge₂O₇ units and such expansion of a germanato‐polyxovanadate was never observed before. The characterization of these compounds revealed the presence of two protonated tren molecules charge balancing the negative charges of the [{M(tren)}₄V₁₅Ge₆O₄₈(H₂O)]^4– anion.     

Synthesis and crystal structure of 2‐amino‐3‐hydroxypyridinium dioxido(pyridine‐2,6‐dicarboxylato‐κ3O2,N,O6)vanadate(V) and its conversion to nanostructured V2O5

2‐Amino‐3‐hydroxypyridinium dioxido(pyridine‐2,6‐dicarboxylato‐κ³O²,N,O⁶)vanadate(V), (C₅H₇N₂O)[V(C₇H₃NO₄)O₂] or [H(amino‐3‐OH‐py)][VO₂(dipic)], (I), was prepared by the reaction of VCl₃ with dipicolinic acid (dipicH₂) and 2‐amino‐3‐hydroxypyridine (amino‐3‐OH‐py) in water. The compound was characterized by elemental analysis, IR spectroscopy and X‐ray structure analysis, and consists of an anionic [VO₂(dipic)]⁻ complex and an H(amino‐3‐OH‐py)⁺ counter‐cation. The V^V ion is five‐coordinated by one O,N,O′‐tridentate dipic dianionic ligand and by two oxide ligands. Thermal decomposition of (I) in the presence of polyethylene glycol led to the formation of nanoparticles of V₂O₅. Powder X‐ray diffraction (PXRD) and scanning electron microscopy (SEM) were used to characterize the structure and morphology of the synthesized powder.     

Crystallographic report: [Bis(3‐pyridylacrylato)cadmium(II)]n

In [bis(3‐pyridylacrylato)cadmium(II)]_n, the local coordination geometry around the cadmium center is based on an octahedron. The carboxylate acts as a tridentate ligand by bridging two cadmium atoms and binds a third cadmium atom via the pyridyl group with the result that a two‐dimensional layered network is formed. Copyright © 2005 John Wiley & Sons, Ltd.     

{Na2[μ2-(C6H4O2)2](C6H4OOH)2}4-的结构及其在固态合溶液中的NMR比较

The new compound （NH3CH2CH2NH3）2{Na2[μ2-（C6H4O2）2]（C6H4OOH）2} has been synthesized and characterized by elemental analysis, IR, UV, NMR and single crystal X-ray diffraction. The yellow crystals crystallized in the triclinic system with space group P-1 and a=0.6091（2） nm, b= 1.0274（3） nm, c= 1.2466（4） nm, α=89.073（6）°, β=89.376（6）°, γ=78.873（5）°, V=0.7653（4） nm^3, Z= 1, R1=0.0568, wR2=0.1198. Every sodium ion coordinates in trigonal prismatic fashion with two O atoms from a terminal chelating catecholato ligand and four O atoms from bridging P2 catecholato ligands, Two neighboring NaO6 trigonal prisms are face-shared and centrosymmetric with regard to the inversion center consisting of four tri-bridging O atoms to form a binuclear cluster {Na2[μ2-（C6H4O2）2]}^2- anion. The comparison of ^13C NMR spectrum of tlie complex in solid state with that in solution indicated that the rapid exchange between the bridging [μ2-（C6H4O2]^2- and terminal [C6H4OOH]^- ligands was present in solution.     

Regioselective synthesis and characterization of monovanadium‐substituted β‐octamolybdate [VMo7O26]5−

The monovanadium‐substituted polyoxometalate anion [VMo₇O₂₆]^5?, exhibiting a β‐octamolybdate archetype structure, was selectively prepared as pentapotassium [hexaikosaoxido(heptamolybdenumvanadium)]ate hexahydrate, K₅[VMo₇O₂₆]·6H₂O ( VMo₇ ), by oxidation of a reduced vanadomolybdate solution with hydrogen peroxide in a fast one‐pot approach. X‐ray structure analysis revealed that the V atom occupies a single position in the cluster that differs from the other positions by the presence of one doubly‐bonded O atom instead of two terminal oxide ligands in all other positions. The composition and structure of VMo₇ was also confirmed by elemental analyses and IR spectroscopy. The selectivity of the synthesis was inspected by a ⁵¹V NMR investigation which showed that this species bound about 95% of V^V in the crystallization solution. Upon dissolution of VMo₇ in aqueous solution, the [VMo₇O₂₆]^5? anion is substantially decomposed, mostly into [VMo₅O₁₉]^3?, α‐[VMo₇O₂₆]^4? and [V₂Mo₄O₁₉]^4?, depending on the pH.     

Crystallographic report: Octameric sodium trimethylsilanolate hemihydrate hemi‐THF solvate, [$\hbox{NaOSiMe}_{3}{ \cdot} {1 \over 2} \hbox{H}_{2}\hbox{O}{\cdot} {1 \over 2}$THF]8

The title compound is composed of two Na₄O₄ heterocubanes which are connected via four µ‐OSiMe₃ groups. The oxygen atoms of the water molecules occupy two corners of an Na₄O₄ cube and additionally form hydrogen bonds to the µ‐OSiMe₃ groups with O·O distances in the range 2.649(4)–2.714(4) Å. Copyright © 2004 John Wiley & Sons, Ltd.     

Solvothermal Syntheses of (H_2en)_2Sn_2S_6·en and[(H_2hmda)_3(Hhmda)_2](Sn_2S_6)_2Using SnCl_4 and S_8 as Starting Materials

1 INTRODUCTION Since Bedard et al. reported microporous tin(IV) sulfides synthesized by hydrothermal method in the presence of organic amine in 1989[1, 2], a number of thiostannates have been synthesized using hydro- or solvothermal techniques with organic amines as tem- plates. The structures of the resulting tin(IV) sulfi- des are related to the types of organic amines. Two- dimensional polyanions of the types of [Sn3S7]2- and [Sn4S9]2-, which are denoted as SnS-1 and SnS-3, respe…     

ChemInform Abstract: Electronic Structure of the α and β Isomers of [Mo8O26]4‐

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.     

[Co(enMe)_3]_2[As_8V_(14)O_(42)(H_2O)]·10H_2O的水热合成、性质和晶体结构

合成了一种新的砷-钒-氧簇合物[Co(enMe)3]2[As8V14O42(H2O)]10H2O(enMe为1,2-丙二胺),用元素分析、IR和TGA-DTA等进行了表征,并用X射线衍射法测定了晶体结构。结果表明,该晶体属单斜晶系,C2/c空间群,晶胞参数a=28.990(7),b=15.540(6),c=22.77(1),b=131.24(4),Mr=2744.68,V=7714(7)3,Z=4,F(000)=5232,m(MoKa)=7.239mm-1,Dc=2.363g/cm3,R=0.069,Rw=0.073。结构测定表明,结构中簇阴离子[As8V14O42(H2O)]4-与配位阳离子[Co(enMe)3]2+之间靠静电作用相结合,同时通过氢键构成无限的三维骨架结构。     

Synthesis,Structure and in vitro Antitumor Activity of a Multinuclear Diorganotin(IV) Complex [(n‐Bu)4Sn2{2,5‐F2C6H3C(O)NHO}2{2,5‐F2C6H3C(NO)O}]2

A new multinuclear dibutyltin(IV) complex [(n‐Bu)₄Sn₂{2,5‐F₂C₆H₃C(?O)NHO}₂{2,5‐F₂C₆H₃C(?NO)O}]₂ 1 , was synthesized and structurally characterized by melting point measurement, elemental analysis, FT‐IR, ¹H, ¹³C, ¹¹⁹Sn NMR spectroscopies, and X‐ray diffraction analysis. The complex exhibited in vitro antitumor activity against a murine sarcoma carcinoma cell line (S‐180), which was higher than that of 5‐fluorouracil (5‐Fu), currently used clinically as an antitumor agent.     

Facile Synthesis of Well‐Dispersed Silver Nanoparticles on Hierarchical Flower‐like Ni3Si2O5(OH)4 with a High Catalytic Activity towards 4‐Nitrophenol Reduction

Layered nickel silicate nanoflowers (NSFs) with a hierarchical nanostructure have been successfully fabricated by a template‐free solvothermal method. The as‐prepared nanoflowers were composed of many interconnected edge‐curving lamellae with a thickness of about 15 nm and had a high specific surface area (279 m² g^?1) and large pore volume (0.67 cm³ g^?1). The highly dispersed small silver nanoparticles (AgNPs) were immobilized on the surface of NSFs through the in situ reduction of Ag⁺ by Sn²⁺. The AgNP/NSF nanocomposites showed a high performance in the catalytic reduction of 4‐nitrophenol. In particular, there was no visible decrease in the catalytic activity of the reused catalysts even after being recycled four times. The as‐prepared AgNP/NSF nanocomposites might be an excellent catalyst owing to their availability, formability, chemical and thermal stability, and high specific surface area.     

Synthesis and Structural Characterization of Two Molybdenum~phosphate Cluster Compounds: (C_(14)N_(14)H_(63) )Na(H_2Mo_6P_4O_(31))_2·8H_2Oand(C_(14)N_(14)H_(63))Na(H_2Mo_6P_4O_(31) )_2·5H_2O

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