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.
VIV oxyfluorides are of interest as frustrated magnets. The successful synthesis of two‐dimensionally connected vanadium(IV) oxyfluoride structures generally requires the use of ionic liquids as solvents. During solvothermal synthesis experiments aimed at producing two‐ and three‐dimensional vanadium(IV) selenites with triangular lattices, the title compound, diaquatetra‐μ‐fluorido‐dioxidodivanadium(IV) monohydrate, V2O2F4(H2O)2·H2O, was discovered and features a new infinite V4+‐containing two‐dimensional layer comprised of fluorine‐bridged corner‐ and edge‐sharing VOF4(H2O) octahedral building units. The synthesis was carried out under solvothermal conditions. The V4+ centre exhibits a typical off‐centring, with a short V=O bond and an elongated trans‐V—F bond. Hydrogen‐bonded water molecules occur between the layers. The structure is related to previously reported vanadium oxyfluoride structures, in particular, the same layer topology is seen in VOF3.  相似文献   

2.
Single crystals of fluoride hydrates Mn3F8 · 12 H2O and AgMnF4 · 4 H2O have been prepared and characterized by X-ray methods. Mn3F8 · 12 H2O crystallizes in the space group P1 (a = 623.0(3), b = 896.7(4), c = 931.8(4) pm, α = 110.07(2)°, β = 103.18(2)°, γ = 107.54(2)°, Z = 1); AgMnF4 · 4 H2O crystallizes in the space group P21/m (a = 700.9(2), b = 726.1(1), c = 749.4(3) pm, β = 107.17(3)°, Z = 2). Both structures contain Jahn-Teller-distorted [Mn(H2O)2F4]? anions as well as crystal water molecules and exhibit a complex hydrogen bond network between anions and cations, i. e. [Mn(H2O)6]2+ for the first and a polymeric [Ag(H2O)2]? cation for the second compound.  相似文献   

3.
Blue needle—shaped crystals of [Cu(bpy)(H2O)2(C4H4O4)]· 2H2O were obtained by slow evaporation of a methanolic aqueous solution containing a fresh Cu(C4H4O4)· 2H2O precipitate, 4, 4′—bipyridine, and ammonia. Within the complex, the six—coordinated Cu atoms are linked by bis—monodentate gauche succinate anions into chains propagating helically around the [001] axis. The chains are interconnected by 4, 4′—bipyridine ligands into a 3D framework with the crystal H2O molecules located in the channels along the [100], [010] and [110] directions. The Cu2+ ions are in distorted octahedral coordination of two nitrogen and four oxygen atoms (equatorial bonds: Cu—N 1.986(5), 2.015(5)Å; Cu—O 1.950(6), 1.954(6)Å; axial bonds Cu—O: 2.524(9), 2.539(8)Å). Furthermore, the thermal and magnetic behavior of the compound will be discussed. Crystal data: hexagonal, P61 (no. 169), a = 11.066(2)Å, c = 24.965(5)Å, V = 2647.5(8)Å3, Z = 6, R = 0.0528 and wR2 = 0.1103 for 1426 observed reflections (Fo2 > 2σ(Fo2)) out of 2170 unique reflections.  相似文献   

4.
The title compound, tetrakis(tetraethylammonium) cyclo‐tetra‐μ‐oxo‐tetrakis[dioxovanadium(V)] dihydrate, (C8H20N)4[V4O12]·2H2O, was obtained by reacting V2O5 with (C2H5)4NOH. It consists of a discrete centrosymmetric molecular anion, [V4O12]4?, where four tetrahedral VO4 units share two vertices with each other to form a ring. A water mol­ecule is attached on each side of the ring through hydrogen bonds.  相似文献   

5.
The crystal structures of tricopper decavanadate tetracosa­hydrate, (I), and copper tetra­sodium decavanadate tricosa­hydrate, (II), have been determined by single‐crystal X‐ray diffraction. Both compounds exhibit a catenary structure consisting of [V10O28]6− anions linked by Cu2+ cations in (I) or by Na+ cations in (II). Compound (II) also contains a polymeric linear array of edge‐sharing [Na(OH2)6]+ and [Cu(OH2)6]2+ octahedra. In both compounds, the [V10O28]6− ions lie about inversion centres and the Cu2+ ions in (I) also lie about inversion centers.  相似文献   

6.
郭鸿旭  王庆华  陈晨  梁敏  陈铃 《中国化学》2008,26(4):640-644
水热合成并通过红外、热重、单晶X-射线衍射表征了一个新颖镍配位阳离子修饰的还原型钼磷酸盐,Ni[Mo6O12(OH)3(PO4)(HPO4)3]2][Ni(H2O)2][Ni(H2O)(bipy)2]4·5H2O。单晶X-射线衍射研究表明,两个{Mo6P4}簇单元通过一个镍离子连接形成一个Ni[Mo6P4]2二聚结构单元,其进一步和其他的镍配位阳离子连接成钼磷酸盐一维链状结构。在H2O2存在下的液-固体系中,使用该化合物催化氧化苯甲醛的探针反应结果表明,该化合物具有较高的催化氧化活性。  相似文献   

7.
Dicaesium divanadium trioxide phosphate hydrogenphosphate, Cs2V2O3(PO4)(HPO4), (I), and dicaesium tris[oxidovanadate(IV)] hydrogenphosphate dihydrate, Cs2[(VO)3(HPO4)4(H2O)]·H2O, (II), crystallize in the monoclinic system with all atoms in general positions. The structures of the two compounds are built up from VO6 octahedra and PO4 tetrahedra. In (I), infinite chains of corner‐sharing VO6 octahedra are connected to V2O10 dimers by phosphate and hydrogenphosphate groups, while in (II) three vanadium octahedra share vertices leading to V3O15(H2O) trimers separated by hydrogenphosphate groups. Both structures show three‐dimensional frameworks with tunnels in which Cs+ cations are located.  相似文献   

8.
The crystal structures of dimagnesium disodium decavanadate icosahydrate, Mg2Na2V10O28·20H2O, (I), and trimagnesium decavanadate octacosahydrate, Mg3V10O28·28H2O, (II), have been determined by single‐crystal X‐ray diffraction. They crystallize with monoclinic (C2/c) and triclinic () symmetry, respectively. All the Mg2+ cations in (I) and (II) are octahedrally coordinated by six water mol­ecules. The Na+ cations in (I) are coordinated by three water mol­ecules and three O atoms of the decavanadate anions, and link the latter into a three‐dimensional network. The decavanadate anions in (II) are not linked to one another.  相似文献   

9.
The compounds (NMe4)5[As2Mo8V4AsO40] · 3 H2O 2a , (NH4)21[H3Mo57V6(NO)6O183(H2O)18] · 65 H2O 3a , (NH2Me2)18(NH4)6[Mo57V6(NO)6O183(H2O)18] · 14 H2O 3b and (NH4)12[Mo36(NO)4O108(H2O)16] · 33 H2O 4a ( 3a and 4a were not correctly reported in the literature regarding to their composition, structures and the oxidation states of the metal centres) which contain large isolated anionic species, have been prepared (among them 3a, 3b , and 4a in rather high yield) and characterized by complete crystal structure analysis as well as IR/Raman, UV/VIS/NIR, ESR spectroscopy and magnetic susceptibility measurements, redox titrations, bond valence sum calculations, elemental analyses and thermogravimetric studies. Perspectives for polyoxometalate chemistry referring to the synthesis of “extremely” large nanoscaled species are discussed, together with the occurrence of a large transferable {Mo17} building block in the compounds 3a, 3b and 4a which also exists in the corresponding iron compound Na3(NH4)12[H15Mo57Fe6(NO)6O183(H2O)18] · 76 H2O 7a .  相似文献   

10.
The crystal structure of (AsPh4)2[ReN(H2O)(CN)4]·5H2O has been determined from three-dimensional X-ray diffraction data. The yellow crystals are monoclinic, space group P21/n with cell dimensionsa=15.482(1),b=19.950(2),c=16.999(1)? and β=101.69(6)o,Z=4,D expt=1.48(1)g cm−3 andD calc=1.52g cm−3. The anisotropic refinement of 7858 observed reflections converged toR=0.055. The [ReN(H2O)(CN)4]2− ion has a distorted octahedral geometry. Bond distances: Re≡N=1.639(8), Re−OH2=2.496(7) and Re−C(av)=2.11(1) ?. The rhenium atom is displaced by 0.35 ? out of the plane formed by the four carbon atoms of the cyano ligands towards the terminal nitrido ligand. TMC 2479  相似文献   

11.
[Cd(H2O)3(C5H6O4)]·2H2O ( 1 ) and Cd(H2O)2(C6H8O4) ( 2 ) were prepared from reactions of fresh CdCO3 precipitate with aqueous solutions of glutaric acid and adipic acid, respectively, while Cd(H2O)2(C8H12O4) ( 3 ) crystallized in a filtrate obtained from the hydrothermal reaction of CdCl2·2.5H2O, suberic acid and H2O. Compound 1 consists of hydrogen bonded water molecules and linear {[Cd(H2O)3](C5H6O4)2/2} chains, which result from the pentagonal bipyramidally coordinated Cd atoms bridged by bis‐chelating glutarato ligands. In 2 and 3 , the six‐coordinate Cd atoms are bridged by bis‐chelating adipato and suberato ligands into zigzag chains according to {[Cd(H2O)3](C5H6O4)2/2} and {[Cd(H2O)2](C8H12O4)2/2}, respectively. The hydrogen bonds between water and the carboxylate oxygen atoms are responsible for the supramolecular assemblies of the zigzag chains into 3D networks. Crystallographic data: ( 1 ) P1¯ (no. 2), a = 8.012(1), b = 8.160(1), c = 8.939(1) Å, α = 82.29(1)°, β = 76.69(1)°, γ = 81.68(1)°, U = 559.6(1) Å3, Z = 2; ( 2 ) C2/c (no. 15), a = 16.495(1), b = 5.578(1), c = 11.073(1) Å, β = 95.48(1)°, U = 1014.2(1) Å3, Z = 4; ( 3 ) P2/c (no. 13), a = 9.407(2), b = 5.491(1), c = 11.317(2) Å, β = 95.93(3)°, U = 581.4(2) Å3, Z = 2.  相似文献   

12.
Preparation of Ceramic Powders. IX. NiMn2O4 and ZnMn2O4 Formation by Decomposition of [Ni(H2O)6] (MnO4)2 and [Zn(H2O)6] (MnO4)2 Improved preparation of Ba(MnO4)2 from BaMnO4 is reported. Thermal or hydrothermal decomposition of [Ni(H2O)6] (MnO4)2 yields intermediately an amorphous manganate(IV) which forms crystalline NiMnO3 and α-Mn2O3 in the range T > 400°C. NiMn2O4 is formed above 730°C in accordance with the phase diagram. On the other hand, ZnMn2O4 is already at 300°C obtained from [Zn(H2O)6](MnO4)2 at hydrothermal conditions.  相似文献   

13.
The compounds (I)-(IV) are prepared by reaction of V2O5 with 40% HF in the presence of suitable amounts of the corresponding cations.  相似文献   

14.
Single crystals of three rubidium uranyl selenates, Rb2[(UO2)(SeO4)2(H2O)](H2O) ( 1 ), Rb2[(UO2)2(SeO4)3(H2O)2](H2O)4 ( 2 ), and Rb4[(UO2)3(SeO4)5(H2O)] ( 3 ), have been prepared by evaporation from aqueous solutions made out of mixtures of uranyl nitrate, selenic acid and Rb2CO3. The structures of all compounds have been solved by direct methods on the basis of X‐ray diffraction data sets. The crystallographic data are as follows: ( 1 ): orthorhombic, Pna21, a = 13.677(2), b = 11.8707(13), c = 7.6397(9) Å, V = 1240.4(3) Å3, R1 = 0.045 for 2396 independent observed reflections; ( 2 ): triclinic, P1¯, a = 8.4261(12), b = 11.8636(15), c = 13.3279(18) Å, α = 102.612(10), β = 107.250(10), γ = 102.510(10)°, V = 1183.7(3) Å3, R1 = 0.067 for 4762 independent observed reflections; ( 3 ): orthorhombic, Pbnm, a = 11.3761(14), b = 15.069(2), c = 19.2089(17) Å, V = 3292.9(7) Å3, R1 = 0.075 for 3808 independent observed reflections. The structures of the phases 1 , 2 , and 3 are based upon uranyl selenate hydrate sheets composed from corner‐sharing pentagonal [UO7]8— bipyramids and [SeO4]2— tetrahedra. In the crystal structure of 1 , the sheets have composition [(UO2)(SeO4)2(H2O)]2— and run parallel to (001). The interlayer contains Rb+ cations and additional H2O molecules. In structure of 2 , the [(UO2)2(SeO4)3(H2O)2]2— sheets are oriented parallel to (101). Highly disordered Rb+ cations and H2O molecules are located between the sheets. The structure of 3 is based upon [(UO2)3(SeO4)5(H2O)]4— sheets stacked parallel to (010) and contains Rb+ cations in the interlayers. The topologies of the uranyl oxoselenate sheets observed in the structures of 1 , 2 , and 3 are related to the same simple and highly‐symmetric graph consisting of 3‐connected white and 6‐connected black vertices.  相似文献   

15.
The crystal and molecular structure of dipotassium di‐μ‐oxo‐bis[aqua(oxalato‐O1,O2)oxomolybdenum(III)] trihydrate, K2­[Mo2O4(C2O4)2(H2O)2]·3H2O, has been determined from X‐ray diffraction data. In the dimeric anion, which has approximate twofold symmetry, each Mo atom is in a distorted octahedral coordination, being bonded to one terminal oxo‐O atom, two bridging O atoms, two O atoms from the oxalato ligand and one from the water mol­ecule. Bond lengths trans to the multiple‐bonded terminal oxo ligand are larger than those in the cis position, confirming the trans influence as a generally valid rule.  相似文献   

16.
Phase composition of the V2O5-NaVO3-Ca(VO3)2-Mn2V2O7 system was studied, and a subsolidus phase diagram constructed. The tetrahedration of the diagram is determined by the fact that the end-member of Ca1–x Mn x (VO3)2 solid solution is in equilibrium with all compounds of the system (V2O5, NaVO3, Ca(VO3)2), vanadium β-bronzes Na x V2O5 (0.22 ≤ x ≤ 0.40) and κ-bronzes (0.25 ≤ x ≤ 0.45, 0 ≤ y ≤ 0.16), Mn2V2O7, and Na2Mn3(V2O7)2 and with the end-members of reciprocal solid solutions based on calcium and sodium metavanadates. At 20°C, the degree of vanadium dissolution α for Na2Ca(VO3)4 is 100% for 0.5 ≤ pH ≤ 10; for the other phases of the system, vanadium dissolution ranges from 100 to 10% for pH below 3.5; in the alkaline pH range, ≤ 10%. Sodium for calcium substitution in Ca(VO3)2 increases α in aqueous NaOH to 20%. For Na2Mn3(V2O7)2, α decreases from 92 to 80% as pH changes from 0.5 to 2.5; at pH above 4, α = 30%.  相似文献   

17.
Acidic Sulfates of Neodymium: Synthesis and Crystal Structure of (H5O2)(H3O)2Nd(SO4)3 and (H3O)2Nd(HSO4)3SO4 Light violett single crystals of (H5O2)(H3O)2 · Nd(SO4)3 are obtained by cooling of a solution prepared by dissolving neodymium oxalate in sulfuric acid (80%). According to X‐ray single crystal investigations there are H3O+ ions and H5O2+ ions present in the monoclinic structure (P21/n, Z = 4, a = 1159.9(4), b = 710.9(3), c = 1594.7(6) pm, β = 96.75(4)°, Rall = 0.0260). Nd3+ is nine‐coordinate by oxygen atoms. The same coordination number is found for Nd3+ in the crystal structure of (H3O)2Nd(HSO4)3SO4 (triclinic, P1, Z = 2, a = 910.0(1), b = 940.3(1), c = 952.6(1) pm, α = 100.14(1)°, β = 112.35(1)°, γ = 105.01(1)°, Rall = 0.0283). The compound has been prepared by the reaction of Nd2O3 with chlorosulfonic acid in the presence of air. In the crystal structure both sulfate and hydrogensulfate groups occur. In both compounds pronounced hydrogen bonding is observed.  相似文献   

18.
The Layered Structure of Cu2(H2O)4[C4H4N2][C6H2(COO)4]·2H2O Triclinic single crystals of Cu2(H2O)4[C4H4N2][C6H2(COO)4]·2H2O have been grown in an aqueous silica gel. Space group (Nr. 2), a = 723.94(7) pm, b = 813.38(14) pm, c = 931.0(2) pm, α = 74.24(2)°, β = 79.24(2)°, γ = 65.451(10)°, V = 0.47819(14) nm3, Z = 1. Cu2+ is coordinated in a distorted, octahedral manner by two water molecules, three oxygen atoms of the pyromellitate anions and one nitrogen atom of pyrazine (Cu—O 194.1(2)–229.3(3) pm; Cu–N 202.0(2) pm). The connection of Cu2+ and [C6H2(COO)4)]4? yields infinite strands, which are linked by pyrazine molecules to form a two‐dimensional coordination polymer. Thermogravimetric analysis in air showed that the dehydrated compound was stable between 175 and 248 °C. Further heating yielded CuO.  相似文献   

19.
Single crystals of potassium iron hydrogen phosphate, KFe3(HPO4)2(H2PO4)6 · 4 H2O, were prepared hydrothermally by heating a mixture of Fe2O3, H3PO4 and K2CO3 with a small amount of water. It crystallizes monoclinic, space group C2/c (N° 15 Int. Tab.) with Z = 4 and a = 1701(2), b = 960.4(5), c = 1750(1) pm, β = 90.88(7)°. The crystal structure was solved by using 1716 unique reflections F0 > 4σ(F0) with a final wR2 value of 0.126 (SHELXL-93). The main feature of the crystal structure are layers formed by PO4-tetrahedra around the FeO6-octahedra parallel to (001). K+ and H2O molecules connect these layers. Effective Coordination Numbers (ECoN), Mean Fictive Ionic Radii (MEFIR), Charge Distribution (CHARDI) and the Madelung Part of Lattice Energy (MAPLE) are calculated for the title compound. The existence of hydrogen bonds is confirmed by these calculations.  相似文献   

20.
A new molybdenum complex (C4H12N2)2[(MoV2O4)(MoVIO4)(C2O4)2]·2H2O, was solvothermally synthesized and characterized by single-crystal X-ray diffraction. The structure of the compound consists of oxalate acid-coordinated mixed-valent [MoV2O4][MoVIO4] helical chains and protonated piperazine cations. The helical chains are built up from the [MoV2O4] units and [MoVIO4] tetrahedral. The central axis about helical chain is a 2-fold screw axis. The compound crystallizes in the space group P21/n of monoclinic system with a = 11.396(2) Å, b = 14.107(3) Å, c = 15.805(3) Å, β = 102.09(3)°, V = 2484.6(9) Å3, Z = 4. Other characterizations by elemental analysis, IR, and thermal analysis for this compound are also given.  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