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 94 毫秒
1.
Barium Stannate Powders from Hydrothermal Synthesis and by Thermolysis of Barium‐Tin(IV)‐Glycolates. Synthesis and Structure of [Ba(C2H6O2)4][Sn(C2H4O2)3] and [Ba(C2H6O2)2][Sn(C2H4O2)3]·CH3OH The hydrothermal reaction as well as the microwave assisted hydrothermal reaction of SnO2·aq with barium hydroxide gives Ba[Sn(OH)6] ( 1 ) as powder with bar like particles. Compound 1 of the same morphology can also be isolated from a hydrothermal reaction of [Ba(C2H6O2)4][Sn(C2H4O2)3] ( 3 ). The reaction of SnO2·aq with Ba(OH)2·8H2O in ethylene glycol yields the glycolate [Ba(C2H6O2)4][Sn(C2H4O2)3] ( 3 ), which forms in methanol the solvate [Ba(C2H6O2)2][Sn(C2H4O2)3]·CH3OH ( 4 ). Compounds 1 , 3 and 4 react at different temperatures to BaSnO3 ( 2 ) consisting of powders with different morphologies; because of the grain size of the resulting powders compounds 3 and 4 are suitable as precursor for the fabrication of corresponding ceramics.  相似文献   

2.
Crystal Structures of Sr(OH)2 · H2O, Ba(OH)2 · H2O (o.-rh. and mon.), and Ba(OH)2 · 3 H2O The crystal structures of Ba(OH)2 · 3 H2O (Pnma, Z = 4), γ-Ba(OH)2 · H2O (P21/m, Z = 2) and the isotypic Sr(OH)2 · H2O and β-Ba(OH)2 · H2O (Pmc21, Z = 2) were determined using X-ray single crystal data. Ba(OH)2 · 3 H2O and Ba(OH)2 · H2O mon. crystallize in hitherto unknown structure types. The structure of Ba(OH)2 · H2O mon. is strongly related to that of rare earth hydroxides M(OH)3 with space group P63/m (super group of P21/m). The metal-oxygen distances are significantly shorter for OH? ions (mean Ba—O bond lengths of all hydroxides under investigation 278.1 pm) than for H2O molecules (289.9 pm). Corresponding to other hydrates of ionic hydroxides, the water molecules form strong hydrogen bonds to adjacent OH? ions whereas the hydroxide are not H-bonded.  相似文献   

3.
Bis(disulfido)bridged NbIV cluster oxalate complexes [Nb2(S2)2(C2O4)4]4– were prepared by ligand substitution reaction from the aqua ion [Nb2(μ‐S2)2(H2O)8]4+ and isolated as K4[Nb2(S2)2(C2O4)4] · 6 H2O ( 1 ), (NH4)6[Nb2(S2)2(C2O4)4](C2O4) ( 2 ) and Cs4[Nb2(S2)2(C2O4)4] · 4 H2O ( 3 ). The crystal structures of 1 and 2 were determined. The crystals of 1 belong to the space group P1, a = 720.94(7) pm, b = 983.64(10) pm, c = 1071.45(10) pm, α = 109.812(1)°, β = 91.586(2)°, γ = 105.257(2)°. The crystals of 2 are monoclinic, space group C2/c, a = 1567.9(2) pm, b = 1906.6(3) pm, c = 3000.9(4) pm, β = 95.502(2)°. The packing in 2 shows alternating layers of cluster anions and of ammonium/uncoordinated oxalates perpendicular to the [1 0 1] direction. Vibration spectra, electrochemistry and thermogravimetric properties of the complexes are also discussed.  相似文献   

4.
Syntheses and Crystal Structures of the Polyselenido Complexes (PPh4)6[M(Se4)2]2[WSe4] · DMF with M = Zinc and Mercury The title compounds have been prepared by the reactions of the acetates of zinc and mercury, respectively, with excess (PPh4)2 WSe4 in boiling dimethylformamide, forming black-red single crystals. According to the X-ray structure determinations both compounds crystallize isotypically in the space group 12/a with four formula units per unit cell. (PPh4)6[Zn(Se4)2]2[WSe4] · DMF: a = 2888.1(6), b = 1740.3(2), c = 2893.9(4) pm, β = 90.47(1)°. 3230 observed unique reflections, R = 0.009. (PPh4)6[Hg(Se4)2]2[WSe4] · DMF: a = 2891.8(5), b = 1738.0(4), c = 2920.1(5) pm, β = 90.29(2)°. 2978 observed unique reflections, R = 0.115%. The compounds consist of PPh4+ ions, spirocyclic octaseleno metallates [M(Se4)2]2?, tetrahedral WSe42-ions, and disordered DMF Molecules.  相似文献   

5.
The mechanochemical synthesis offers an easy access to obtain alkaline earth metal terephthalates M(C8H4O4) · nH2O (M = Ca, Sr, Ba). In the presented study we describe for the first time the mechanochemical synthesis of powders of Ca(C8H4O4) · 3H2O, Ca(C8H4O4), Sr(C8H4O4) · H2O, and Ba(C8H4O4), which so far were only synthesized as single crystals from aqueous solutions or by reactions in an autoclave. Furthermore, a new hydrate Ba(C8H4O4) · 2(1.5)H2O, not described so far in the literature, was prepared. All compounds were characterized by X‐ray powder diffraction, thermal analysis, elemental analysis, FT‐IR, and MAS NMR spectroscopic measurements.  相似文献   

6.
Complexes with Substituted 2,5-Dihydroxy-p-benzochinones: EAC6(C6H5)2O4 · 4 H2O (EA = Sr2+, Ba2+) Single crystals of the isotypic compounds EAC6(C6H5)2O4 · 4 H2O were grown in aqueous silicagel. EA2+ has CN 8. It is surrounded by four water molecules and four oxygen atoms of the bis-chelating polyporate dianions. Thereby folded chains are formed which are interlinked by hydrogen bonds. Thus building up corrugated layers with the phenyl substituents almost perpendicular to the layer plane. The layer stacking provides that they can engage into another.  相似文献   

7.
Alkaline Molybdotellurates: Preparation and Crystal Structures of Rb6[TeMo6O24] · 10H2O and Rb6[TeMo6O24] · Te(OH)6 · 6H2O Single crystals of Rb6[TeMo6O24] · 10 H2O and Rb6[TeMo6O24] · Te(OH)6 · 6 H2O, respectively, were grown from aqueous solution. Rb6[TeMo6O24] · 10 H2O possesses the space group P1 . The lattice dimensions are a = 963.40(13), b = 972.56(12), c = 1 056.18(13) pm, α = 97.556(10), β = 113.445(9), γ = 102.075(10)°; Z = 1, 2 860 reflections, 215 parameters refined, Rg = 0.0257. The centrosymmetrical [TeMo6O24]6? anions are stacked parallel to [010]. Rb(2) is coordinated with one exception by water molecules only. Folded chains consisting of [TeMo6O24]6? anions and Rb(2) coordination polyhedra which are linked to pairs represent the prominent structural feature. Rb6[TeMo6O24] · Te(OH)6 · 6 H2O crystallizes monoclinically in the space group C2/c with a = 1 886.4(3), b = 1 000.9(1), c = 2 126.5(3) pm, and β = 115.90(1)°; Z = 4, 3 206 reflections, 240 parameters refined, Rg = 0.0333. It is isostructural in high extent with (NH4)6[TeMo6O24] · Te(OH)6 · 7 H2O. Hydrogen bonds between Te(OH)6 molecules and [TeMo6O24]6? anions establish infinite strands. The [TeMo6O24]6? anions gather around Te(OH)6 providing channel-like voids extending parallel to [001].  相似文献   

8.
Double complex salts [Au(C4H13N3)Cl][MCl6nH2O (M = Ir, Pt; n = 0–2) were synthesized. According to X-ray diffraction data, compounds with n = 1.5 are isostructural; the crystal structure is composed of the complex cations [Au(dien)Cl]2+ (dien is diethylenetriamine), the complex anions [MCl6]2−, and water molecules of crystallization. Thermolysis of the double complex salts under hydrogen and helium was studied. The formation of nonequilibrium solid solutions based on Ir in the Au-Ir system and based on Pt in the Au-Pt system was demonstrated. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 416–421, March, 2006.  相似文献   

9.
10.
The structures of the hexafluoridoiridates(IV) of calcium, Ca[IrF6]·2H2O [calcium hexafluoridoiridate(IV) dihydrate], strontium, Sr[IrF6]·2H2O [strontium hexafluoridoiridate(IV) dihydrate], and barium, Ba[IrF6] [barium hexafluoridoiridate(IV)], have been determined by single‐crystal X‐ray analysis. The first two compounds are isomorphous. Their metal cations are eight‐coordinated in a distorted square‐antiprismatic coordination environment, and their anions are represented by an almost ideal octahedron. These two structures can be described as frameworks in which all atoms occupy general positions. Sr[RhF6] and Ba[RhF6] have a different space group (, from powder diffraction data) but similar cell dimensions. The structures are very close to that of Ba[IrF6]. The cation is in a cuboctahedral coordination. The metal atoms are located on special positions of symmetry, while the F atoms are in general positions.  相似文献   

11.
The Cluster Azides M2[Nb6Cl12(N3)6]·(H2O)4—x (M = Ca, Sr, Ba) The isotypic cluster compounds M2[Nb6Cl12(N3)6] · (H2O)4—x (M = Ca (1) , M = Sr (2) and M = Ba (3) ) have been synthesized by the reaction of an aequeous solution of Nb6Cl14 with M(N3)2. 1 , 2 and 3 crystallize in the space group Fd3¯ (No. 227) with the lattice constants a = 1990.03(23), 2015.60(12) and 2043, 64(11) pm, respectively. All compounds contain isolated 16e clusters whose terminal positions are all occupied by orientationally disordered azide ligands.  相似文献   

12.
The reaction of the nitrates M(NO3)3·6H2O (M = La, Pr) and (H3O)2PtCl6 led to yellow single crystals of [M(NO3)2(H2O)6]2[PtCl6]·2H2O (M = La, Pr) (monoclinic, P21/c, Z = 2, La/Pr: a = 697.4(3)/695.5(1), b = 1654.5(1)/1652.5(2), c = 1317.7(6)/1318.5(3) pm, β = 93.97°(7)/93.93°(2), Rall = 0.0169/0.0659) while the reaction of M(NO3)3·5H2O (M = Gd, Dy) and (H3O)2PtCl6 yielded yellow single crystals of [M(NO3)(H2O)7][PtCl6]·4H2O (monoclinic, P21/n, Z = 4, Gd/Dy: a = 838.72(3)/838.40(2), b = 2131.98(6)/2139.50(7), c = 1142.63(3)/1143.10(3) pm, β = 95.670(4)/95.698(3), Rall = 0.0475/0.0337). The crystal structures consist of octahedral [PtCl6]2? anions and complex [M(NO3)2(H2O)6]2+ and [M(NO3)(H2O)7]2+ cations, respectively. The thermal decomposition of both types of compounds leads via various steps to elemental platinum and the oxide chlorides MOCl (M = La, Pr, Gd, Dy).  相似文献   

13.
Polyol Metal Complexes. XIII. Na2[Be(C4H6O3)2] · 5H2O and Na2[Pb(C4H6O3)2] · 3H2O – Two Homoleptic Bis Polyolato Metallates with Beryllium and with Lead Na2[Be(C4H6O3)2] · 5H2O ( 1 ) and Na2[Pb(C4H6O3)2] · 3H2O ( 2 ) crystallize from concentrated, alkaline aqueous solutions. The polyol anhydroerythritol is deprotonated twice in the mononuclear, homoleptic complex anions. The preference of beryllium for the binding of cis-furanoid diols is shown. In 2 , a stereochemically active lone pair at the central atom is the reason for the construction of low dimensional aggregates from three plumbate and three sodium ions.  相似文献   

14.
15.
Cs6[TeMo6O24] · 2 Te(OH)6 · 4 H2O – A Telluric Acid-rich Inclusion Compound Single crystals of Cs6[TeMo6O24] · 2 Te(OH)6 · 4 H2O have been grown from aqueous solution. It crystallizes triclinically in space group P1 with Z = 1, a = 1 086.6(1), b = 1 095.6(1), c = 1 105.5(1) pm, α = 118.83(1), β = 106.22(1) and γ = 100.00(1)°. X-ray structure determination (5 755 reflections, 251 parameters, Rg = 0.0355) revealed an infinite chain consisting of hydrogen bonded (OH …? O 259.4(5) – 267.4(6) pm) Te(OH)6 molecules and [TeMo6O24]6? anions to be the Prominent structural feature. Further hydrogen bonds between neighbouring Te(OH)6 molecules connect these chains to yield a two-dimensionally infinite arrangement.  相似文献   

16.
The thermal decomposition of (NH4)2[Mo3S(S2)6] · nH2O was studied by DTA/TG, infrared spectroscopy, X-ray diffraction, determination of specific surfaces and temperature programmed desorption measurements. The results are reported and discussed with respect to the stability of the MoIV-triangle system which is retained during the thermal treatment up to the formation of hexagonal MoS2, which can be understood nicely from a mechanistic point of view.  相似文献   

17.
Ternary Hydroxides. I. Synthesis, Structure, and Properties of Li2[Sn(OH)6] · 2 H2O Colourless crystals of Li2[Sn(OH)6] · 2 H2O were synthesized by reaction of SnCl4 with LiOH in aqueous solution. The crystal structure was determined from single crystal data. Li2[Sn(OH)6] · 2 H2O: monoclinic, P21/n (Nr. 14), a = 502.3(1), b = 692.3(1), c = 1020.2(3) pm, β = 99.78(1)°, V = 349.6(2) · 106 pm3, Z = 2, R/Rw = 0.0192/0.0472, N(I) > 2σ(I) = 1527, N(Par.) = 54. Within the crystal structure only slightly distorted octahedrally [Sn(OH)6]2? ions are bonded via hydrogen bonds with water molecules forming layers, which themselve are linked by tetrahedrally coordinated Li ions; the structure is in accordance with the IR-data and the results of the 119Sn solid state NMR-spectroscopy; the hydrat water is eliminated at 117.1°C, the condensation reaction – forming the ternary oxide – takes place at 257.7°C.  相似文献   

18.
Characterization of Distortional Isomers of the Anions Pentacyano-oxo-molybdate(IV) and of Tetracyano-aqua-oxo-molybdate(IV) in the Solid State. Crystal Structures of [(C6H5)4P]3[MoO(CN)5] · 7 H2O (green), [(C6H5)4As]2[MoO(OH2)(CN)4] · 4 H2O (blue), and [(C6H5)4P]2[MoO(OH2) (CN)4] · 4 H2O (green) Preparation of a series of salts containing the new pentacyano-oxo-molybdate(IV) anion is described: Cs2H[MoO(CN)5] (blue), [(CH3)4N]2H[MoO(CN)5] · 2 H2O (blue) and [Cr(en)3] [MoO(CN)5] · 4 H2O (green). The green [(C6H5)4P]3[MoO(CN)5] · 7 H2O crystallizes triclinic in the space group P1 . The molybdenum(IV) center is in an pseudo-octahedral environment of a terminal oxo-group (d(Mo?O); 1.705(4) Å), a CN? group in the trans-position (d(Mo? C): 2.373(6) Å), and four equatorial CN? groups (averaged d(Mo? C): 2.178 (Å). The blue and green salts exhibit v(Mo?O) stretching frequencies at 948 cm?1 and 920 cm?1, respectively. Blue and green salts containing the [MoO(OH2)(CN)4]2? anion and [(C6H5)4P]+ or [(C6H5)4As]+ cations have been prepared and characterized by single crystal crystallography. [(C6H5)4P]2[MoO(OH2)(CN)4] · 4 H2O (green) and [(C6H5)4As]2[MoO(OH2)(CN)4] · 4 H2O (blue) crystallize monoclinic in the space group C—P21/n. They are considered to be distortional isomers of the complex anion: the green species has a Mo?O bond distance of 1.72(2) Å whereas for the blue species d(Mo?O) = 1.60(2) Å is found; the corresponding v(Mo?O) frequencies are at 920 cm?1 and 980 cm?1.  相似文献   

19.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 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.  相似文献   

20.
Dicarboxylate Groups as Ligands and Anions in Aquamagnesium Complexes: Crystal Structures of [Mg (C4H2O4)(H2O)4] · H2O and [Mg(H2O)6](C4HO4)2 · 2H2O ((C4H2O4)2— = Fumarate; (C4HO4) = Hydrogenacetylenedicarboxylate) Crystals of tetraaqua(fumarato)magnesium‐hydrate ( 1 ) and hexaaquamagnesium‐bis(hydrogenacetylenedicarboxylate)‐dihydrate ( 2 ) were prepared by reacting MgCl2 with sodium fumarate and acetylenedicarboxylic acid, respectively. In 1 cis‐Mg(H2O)4 units are bridged by α, Ö‐bonded fumarate groups. The resulting zig zag chains exhibit the maximum symmetry compatible with space group symmetry C2/c. 2 consists of layers of voluminous [Mg(H2O)6]2+ cations alternating with layers of C4HO4 anions. The nearly planar anions are held together by parallel stacking and by short hydrogen bonds. Both structures contain efficient H bridging systems. 1 : Space group C2/c, Z = 4, lattice constants at 20 °C: a = 5.298(1), b = 13.178(2), c = 13.374(2)Å; ß = 94.79(2)°, R1 = 0.024. 2 : Space group P1, Z = 1, lattice constants at 20 °C: a = 5.985(1), b = 6.515(1), c = 11.129(1)Å; α = 105.24(2), ß = 91.87(3), γ = 90.92(1)°, R1 = 0.034.  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