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1.
Crystal structure of a series of mixed-metal oxides, T2Mo3O8 (T=Mg, Co, Zn and Mn; P63mc; a=5.7628(1) Å, c=9.8770(3) Å for Mg2Mo3O8; a=5.7693(3) Å, c=9.9070(7) Å for Co2Mo3O8; a=5.7835(2) Å, c=9.8996(5) Å for Zn2Mo3O8; a=5.8003(2) Å, c=10.2425(5) Å for Mn2Mo3O8) was investigated by X-ray diffraction on single crystals. Structural analysis, magnetization measurements, X-ray photoemission spectroscopy and cyclic voltammetry showed that the Mn ions at the tetrahedral and octahedral sites in Mn2Mo3O8 adopt different valences of +2 and 2+δ (δ>0), respectively. The formal valence of the Mo3 in Mn2Mo3O8 is 12−δ to retain electric neutrality of the compound. In contrast, the T ions and Mo3 in T2Mo3O8 (T=Mg, Co and Zn) adopt the valences of +2 and +12, respectively.  相似文献   

2.
The isotypic oxonitridosilicate halides Ce10[Si10O9N17]Br, Nd10[Si10O9N17]Br and Nd10[Si10O9N17]Cl were obtained by the reaction of the respective lanthanide metals, their oxides and halides with “Si(NH)2” in a radiofrequency furnace at temperatures around 1800 °C, using CsBr, resp. CsCl, as a flux. The crystal structures were determined by single-crystal X-ray diffraction (Pbam, no. 55, Z=2; Ce/Br: a=10.6117(9) Å, b=11.2319(10) Å, c=11.688(8) Å, R1=0.0356; Nd/Br: a=10.523(2) Å, b=11.101(2) Å, c=11.546(2) Å, R1=0.0239; Nd/Cl: a=10.534(2) Å, b=11.109(2) Å, c=11.543(2) Å, R1=0.0253) and represent a new layered structure type. The structure refinements were performed utilizing an O/N-distribution model according to Paulings rules, i.e. nitrogen was positioned on all bridging sites and mixed O/N-occupation was assumed on the terminal sites resulting in charge neutrality of the compounds. The layers consist of condensed [SiN2(O/N)2] and [SiN3(O/N)] tetrahedra of Q2 and Q3 type. The chemical composition of the compounds was derived from chemical analyses for Nd10[Si10O9N17]Br and electron probe micro analyses (EPMA) for all three compounds. The results of IR spectroscopic investigations are reported.  相似文献   

3.
The first charge transfer salt based on non- dimerized [BEDO-TTF]+ monocationic radical (BEDO-TTF=bis(ethylenedioxy)tetrathiafulvalene) associated with [Mo6Br14]2− cluster anions has been synthesized by conventional electro-oxidation and characterized by single crystal X-ray diffraction, UV-VIS-NIR absorption and magnetic susceptibility measurements. (BEDO-TTF)2Mo6Br14(PhCN)4 crystallizes in the monoclinic system, space group P21/n, a=10.414(4) Å, b=21.711(7) Å, c=15.958(5) Å, β=93.65(3)°, V=3601(2) Å3, Z=2, R1=0.0578, wR2=0.0731. The structure of this hybrid compound is built up from a [BEDO-TTF]+ and PhCN (benzonitrile) organic framework in which are hosted the [Mo6Br14]2− inorganic cluster units. It results in non- dimerized [BEDO-TTF]+ cations that exhibit a paramagnetic behavior characteristic of one unpaired electron.  相似文献   

4.
Application of high-pressure high-temperature conditions (3.5 GPa at 1673 K for 5 h) to mixtures of the elements (RE:B:S=1:3:6) yielded crystalline samples of the isotypic rare earth-thioborate-sulfides RE9[BS3]2[BS4]3S3, (RE=Dy-Lu), which crystallize in space group P63 (Z=2/3) and adopt the Ce6Al3.33S14 structure type. The crystal structures were refined from X-ray powder diffraction data by applying the Rietveld method. Dy: a=9.4044(2) Å, c=5.8855(3) Å; Ho: a=9.3703(1) Å, c=5.8826(1) Å; Er: a=9.3279(12) Å, c=5.8793(8) Å; Tm: a=9.2869(3) Å, c=5.8781(3) Å; Yb: a=9.2514(5) Å, c=5.8805(6) Å; Lu: a=9.2162(3) Å, c=5.8911(3) Å. The crystal structure is characterized by the presence of two isolated complex ions [BS3]3- and [BS4]5- as well as [□(S2-)3] units.  相似文献   

5.
A new chromium-phosphate has been prepared under hydrothermal conditions for the first time. It crystallizes in the Monoclinic system, space group C2/c, a=17.002(3) Å, b=26.333(5) Å, c=16.017(4) Å, β=96.63 (3)°, V=7123.07(2) Å3 and Z=4. The crystal structure displays a centrosymmetric complex aggregate [Cr9P12O58H12]17−, constructed from the unprecedented enneanucleus chromic core Cr9O10 with peripheral ligations provided by 12 phosphate groups. The sodium ions and water as guests fill in the cavities among the clusters to satisfy the charge balance and keep the structural stability. The magnetic measurement indicates the existence of antiferromagnetic interactions.  相似文献   

6.
A hydrothermal reaction of WO3, CoCl2 and 4,4′-bipyridine, yields a novel organic-inorganic hybrid compound, Co2(bpy)6(W6O19)2, at 170°C. X-ray single crystal structure determination reveals a two-dimensional covalent structure belonging to monoclinic crystal system, space group C2/c, with cell parameters a=19.971(4) Å, b=11.523(2) Å, c=16.138(3) Å, β=96.49(3)°, V=3690.0 Å3 and Z=2. The hexatungstate, [W6O19]2−, acts as a building block in bidentate fashion to bridge the Co(II) centers in the crystal structure. The title compound is found to have an optical energy gap of 2.2 eV from UV-Vis-NIR reflectance spectra.  相似文献   

7.
In order to search for new ionic conductor materials exhibiting a columnar [Bi12O14] structural type, the syntheses of the solid solutions Bi2Mo1−xCrxO6 and Bi26Mo10−xCrxO69 have been undertaken. Single phases were obtained for the last composition with 0≤x≤5 homogeneity range. Moreover, a new oxide with Bi6Cr2O15 composition has been obtained from the limit nominal stoichiometries Bi6CrO6 and Bi26Cr10O69. X-ray powder diffraction studies have shown that this oxide crystallizes in the orthorhombic system, space group Ccc2 or Cccm, with unit-cell parameters a=19.8986(9) Å, b=12.2756(6) Å, c=5.8868(3) Å, and V=1437.96 Å3. Impedance spectroscopy measurements carried out on the representative Bi26Mo8Cr2O69 phase, showed that this material is a good oxygen ion conductor, in fact the best one belongs to the columnar structural type, with a conductivity as high as 1.7×10−3Scm−1 at 425°C.  相似文献   

8.
A nonmetal pentaborate [C6H13N2][B5O6(OH)4] (1) has been synthesized by 1,4-diazabicyclo[2.2.2] octane (DABCO) and boric acid, and characterized by single-crystal X-ray diffraction, FTIR, elemental analysis, and thermogravimetric analysis. Compound 1 crystallizes in the monoclinic system with space group Cc (no. 9), a=10.205(2) Å, b=14.143(3) Å, c=11.003(2) Å, β=113.97(3)°, V=1451.1(5) Å3, Z=4. The anionic units, [B5O6(OH)4], are interlinked via hydrogen bonding to form a three-dimensional (3D) supramolecular network containing large channels, in which the protonated [C6H13N2]+ cations are located. Second-harmonic generation (SHG) measurements on the powder samples reveal that 1 exhibits SHG efficiency approximately 0.9 times that of potassium dihydrogen phosphate (KDP).  相似文献   

9.
Two new hydrated borates, Zn8[(BO3)3O2(OH)3] and Pb[B5O8(OH)]·1.5H2O, have been prepared by hydrothermal reactions at 170 °C. Single-crystal X-ray structural analyses showed that Zn8[(BO3)3O2(OH)3] crystallizes in a non-centrosymmetric space group R32 with a=8.006(2) Å, c=17.751(2) Å, Z=3 and Pb[B5O8(OH)]·1.5H2O in a triclinic space group P1¯ with a=6.656(2) Å, b=6.714(2) Å, c=10.701(2) Å, α=99.07(2)°, β=93.67(2)°, γ=118.87(1)°, Z=2. Zn8[(BO3)3O2(OH)3] represents a new structure type in which Zn-centered tetrahedra are connected via common vertices leading to helical ribbons 1[Zn8O15(OH)3]17− that pack side by side and are further condensed through sharing oxygen atoms to form a three-dimensional 3[Zn8O11(OH)3]9− framework. The boron atoms are incorporated into the channels in the framework to complete the final structure. Pb[B5O8(OH)]·1.5H2O is a layered compound containing double ring [B5O8(OH)]2− building units that share exocyclic oxygen atoms to form a two-dimensional layer. Symmetry-center-related layers are stacked along the c-axis and held together by interlayer Pb2+ ions and water molecules via electrostatic and hydrogen bonding interactions. The IR spectra further confirmed the existence of both triangular BO3 and OH groups in Zn8[(BO3)3O2(OH)3], and BO3, BO4, OH groups as well as guest water molecules in Pb[B5O8(OH)]·1.5H2O.  相似文献   

10.
Two polymorphs of an organic-inorganic hybrid compound, Fe(2,2′-bpy)(HPO4)(H2PO4) (1 and 2) (2,2′-bpy=2,2′-bipyridine), have been synthesized by hydrothermal methods and structurally characterized by single-crystal X-ray diffraction, thermogravimetric analysis, and magnetic susceptibility. Crystal data are as follows: Polymorph 1, monoclinic, space group P21/n (No. 14), a=10.904(2) Å, b=6.423(1) Å, c=19.314(3) Å, β=101.161(3)°, and Z=4; Polymorph 2, monoclinic, space group P21/c (No. 14), a=11.014(1) Å, b=15.872(2) Å, c=8.444(1) Å, β=109.085(3)°, and Z=4. Polymorph 1 adopts a chain structure in which each iron atom is coordinated by two nitrogen atoms from 2,2′-bpy ligand and four phosphate oxygen atoms. These infinite chains are extended into a 3-D supramolecular array via π-π stacking interactions of the lateral 2,2′-bpy ligands. The structure of polymorph 2 consists of the same building units, namely FeO4N2 octahedron, HPO4 and H2PO4 tetrahedra, and 2,2′-bpy ligand, which are linked through their vertices forming an undulated sheetlike structure with 4,12 network. Adjacent layers are extended into a 3-D array via π-π stacking interactions of the aromatic groups. Magnetic susceptibility measurement results confirm that the iron atoms in both compounds are present in the +3 oxidation state.  相似文献   

11.
A new organically templated pentaborate [C6N4H20]0.5[B5O6(OH)4] (1a) was prepared by reactions of triethylenetetramine (TETA) with excess boric acid in aqueous solution and characterized by elemental analysis, FTIR, TG-DTA, powder X-ray diffraction and photoluminescence spectroscopy. The structure of 1a was determined by a single-crystal X-ray diffraction. It crystallizes in the monoclinic system with space group P2(1)/c, a=9200(3) Å, b=14.121(5) Å, c=10.330(4) Å, β=91.512(4)°, V=1341.4(9) Å3, and Z=4. The luminescent properties of the compound were studied, and a green-blue luminescence occurs with an emission maximum at 507 nm upon excitation at 430 nm. The photoluminescence of 1a can be modified from green-blue to white by means of a simple heat-treatment process. The white-light-emission of sample 1c makes the pentaborate a good candidate for display and lighting applications in the white LED.  相似文献   

12.
The paper presents a new data on the crystal structure, thermal expansion and IR spectra of Bi3B5O12. The Bi3B5O12 single crystals were grown from the melt of the same stoichiometry by Czochralski technique. The crystal structure of Bi3B5O12 was refined in anisotropic approximation using single-crystal X-ray diffraction data. It is orthorhombic, Pnma, a=6.530(4), b=7.726(5), c=18.578(5) Å, V=937.2(5) Å3, Z=4, R=3.45%. Bi3+ atoms have irregular coordination polyhedra, Bi(1)O6 (d(B-O)=2.09-2.75 Å) and Bi(2)O7 (d(B-O)=2.108-2.804 Å). Taking into account the shortest bonds only, these polyhedra are considered here as trigonal Bi(1)O3 (2.09-2.20 Å) and tetragonal Bi(2)O4 (2.108-2.331 Å) irregular pyramids with Bi atoms in the tops of both pyramids. The BiO4 polyhedra form zigzag chains along b-axis. These chains alternate with isolated anions [B2IVB3IIIO11]7− through the common oxygen atoms to form thick layers extended in ab plane. A perfect cleavage of the compound corresponds to these layers and an imperfect one is parallel to the Bi-O chains. The Bi3B5O12 thermal expansion is sharply anisotropic (α11α22=12, α33=3×10−6 °C−1) likely due to a straightening of the flexible zigzag chains along b-axis and decreasing of their zigzag along c-axis. Thus the properties like cleavage and thermal expansion correlate to these chains.  相似文献   

13.
A novel three-dimensional inorganic bimetallic compound Cu[Mo3O10]·H2O 1 has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the orthorhombic system, space group Pnma, a=8.6085(17) Å, b=7.5822(15) Å, c=13.690(3) Å, V=893.6(3) Å3, Z=4, λ(MoKα) = 0.71073 Å (R(F)=0.0357 for 1101 reflections). The structure of compound 1 is based on [{Mo3O10}2−] isopolyoxomolybdate chains bonded together with CuO4 tetrahedra into a three-dimensional inorganic open framework. Three types of Mo-Cu layers and one-dimensional tunnels are observed in the title compound.  相似文献   

14.
Although R2O3:MoO3=1:6 (R=rare earth) compounds are known in the R2O3-MoO3 phase diagrams since a long time, no structural characterization has been achieved because a conventional solid-state reaction yields powder samples. We obtained single crystals of R2Mo6O21·H2O (R=Pr, Nd, Sm, and Eu) by thermal decomposition of [R2(H2O)12Mo8O27nH2O at around 685-715 °C for 2 h, and determined their crystal structures. The simulated XRD patterns of R2Mo6O21·H2O were consistent with those of previously reported R2O3:MoO3=1:6 compounds. All R2Mo6O21·H2O compounds crystallize isostructurally in tetragonal, P4/ncc (No. 130), a=8.9962(5), 8.9689(6), 8.9207(4), and 8.875(2) Å; c=26.521(2), 26.519(2), 26.304(2), and 26.15(1) Å; Z=4; R1=0.026, 0.024, 0.024, and 0.021, for R=Pr, Nd, Sm, and Eu, respectively. The crystal structure of R2Mo6O21·H2O consists of two [Mo2O7]2−-containing layers (A and B layers) and two interstitial R(1)3+ and R(2)3+ cations. Each [Mo2O7]2− group is composed of two corner-sharing [MoO4] tetrahedra. The [Mo2O7]2− in the B layer exhibits a disorder to form a pseudo-[Mo4O9] group, in which four Mo and four O sites are half occupied. R(1)3+ achieves 8-fold coordination by O2− to form a [R(1)O8] square antiprism, while R(2)3+ achieves 9-fold coordination by O2− and H2O to form a [R(2)(H2O)O8] monocapped square antiprism. The disorder of the [Mo2O7]2− group in the B layer induces a large displacement of the O atoms in another [Mo2O7]2− group (in the A layer) and in the [R(1)O8] and [R(2)(H2O)O8] polyhedra. A remarkable broadening of the photoluminescence spectrum of Eu2Mo6O21·H2O supported the large displacement of O ligands coordinating Eu(1) and Eu(2).  相似文献   

15.
The uranyl and neptunyl(VI) iodates, K3[(UO2)2(IO3)6](IO3)·H2O (1) and K[NpO2(IO3)3]·1.5H2O (2), have been prepared and crystallized under mild hydrothermal conditions. The structures of 1 and 2 both contain one-dimensional 1[AnO2(IO3)3]1−(An=U,Np) ribbons that consist of approximately linear actinyl(VI) cations bound by iodate anions to yield AnO7 pentagonal bipyramids. The AnO7 units are linked by bridging iodate anions to yield chains that are in turn coupled by additional iodate anions to yield ribbons. The edges of the ribbons are terminated by monodentate iodate anions. For 1 and 2, K+ cations and water molecules separate the ribbons from one another. In addition, isolated iodate anions are also found between 1[UO2(IO3)3]1− ribbons in 1. In order to aid in the assignment of oxidation states in neptunyl containing compounds, a bond-valence sum parameter of 2.018 Å for Np(VI) bound exclusively to oxygen has been developed with b=0.37 Å. Crystallographic data (193 K, MoKα, λ=0.71073): 1, triclinic, , a=7.0609(4) Å, b=14.5686(8)  Å, c=14.7047(8)  Å, α=119.547(1)°, β=95.256(1)°, γ=93.206(1)°, Z=2, R(F)=2.49% for 353 parameters with 6414 reflections with I>2σ(I); (203 K, MoKα, λ=0.71073): 2, monoclinic, P21/c, a=7.796(4)  Å, b=7.151(3)  Å, c=21.79(1)  Å, β=97.399(7)°, Z=4, R(F)=6.33% for 183 parameters with 2451 reflections with I>2σ(I).  相似文献   

16.
A molybdenum (IV) phosphate containing lead, Pb2Mo2(PO4)2P2O7, has been synthesized for the first time. It crystallizes in the space group C2/c with a=14.098(1) Å, b=14.187(2) Å, c=6.5592(4) Å and β=102.08(1)°. Its original tunnel structure, built up of Mo2O11 bioctahedra, P2O7 and PO4 phosphate groups can be described from the assemblage of [Mo4P4O24] ribbons interconnected through monophosphate groups. The stereoactivity of the 6s2 lone pair of Pb2+, which is surrounded by nine oxygen atoms, is discussed.  相似文献   

17.
A novel sodium lead pentaborate, NaPbB5O9, has been successfully synthesized by standard solid-state reaction. The single-crystal X-ray structural analysis showed that NaPbB5O9 crystallizes in the monoclinic space group P21/c with a=6.5324(10) Å, b=13.0234(2) Å, c=8.5838(10) Å, β=104.971(10)°, and Z=4. The crystal structure is composed of double ring [B5O9]3− units, [PbO7] and [NaO7] polyhedra. [B5O9]3− groups connect with each other forming two-dimensional infinite [B5O9]3− layers, while [PbO7] and [NaO7] polyhedra are located between the layers. [PbO7] polyhedra linked together via corner-sharing O atom forming novel infinite [PbO6] chains along the c axis. The thermal behavior, IR spectrum and the optical diffuse reflectance spectrum of NaPbB5O9 were reported.  相似文献   

18.
Hydrothermal synthesis in the K-Mo oxide system was investigated as a function of the pH of the reaction medium. Four compounds were formed, including two K2Mo4O13 phases. One is a new low-temperature polymorph, which crystallizes in the orthorhombic, space group Pbca, with Z=8 and unit cell dimensions a=7.544(1) Å, b=15.394(2) Å, c=18.568(3) Å. The other is the known triclinic K2Mo4O13, whose structure was re-determined from single crystal data; its cell parameters were determined as a=7.976(2) Å, b=8.345(2) Å, c=10.017(2) Å, α=107.104(3)°, β=102.885(3)°, γ=109.760(3)°, which are the standard settings of the crystal lattice. The orthorhombic phase converts endothermically into triclinic phase at ca. 730 K with a heat of transition of 8.31 kJ/mol.  相似文献   

19.
The germanate compound Cu2Sc2Ge4O13 has been synthesized by solid-state ceramic sintering techniques between 1173 and 1423 K. The structure was solved from single-crystal data by Patterson methods. The title compound is monoclinic, a=12.336(2) Å, b=8.7034(9) Å, c=4.8883(8) Å, β=95.74(2), space group P21/m, Z=4. The compound is isotypic with Cu2Fe2Ge4O13, described very recently. The structure consists of crankshaft-like chains of edge-sharing ScO6 octahedra running parallel to the crystallographic b-axis. These chains are linked laterally by [Cu2O6]8− dimers forming a sheet of metal-oxygen-polyhedra within the a-b plane. These sheets are separated along the c-axis by [Ge4O13]10− units. Cooling to 100 K does not alter the crystallographic symmetry of Cu2Sc2Ge4O13. While the b, c lattice parameter and the unit cell volume show a positive linear thermal expansion (α=6.4(2)×10−6, 5.0(2)×10−6 and 8.3(2)×10−6 K−1 respectively), the a lattice parameter exhibits a negative thermal expansion (α=−3.0(2)×10−6 K−1) for the complete T-range investigated. This negative thermal expansion of a is mainly due to the increase of the Cu-Cu interatomic distance, which is along the a-axis. Average bond lengths remain almost constant between 100 and 298 K, whereas individual ones partly show both significant shortages and lengthening.  相似文献   

20.
A new 1,6-hexyldiamine heptaborate, [H3N(CH2)6NH3][B7O10(OH)3] (1), has been solvothermally synthesized and characterized by single-crystal X-ray diffraction, FTIR, elemental analysis, and thermogravimetric analysis. Compound 1 crystallizes in monoclinic system, space group P21/n with a=8.042(2) Å, b=20.004(4) Å, c=10.103(2) Å, and β=90.42(3)°. The anionic [B7O10(OH)3]n2n layers are interlinked via hydrogen bonding to form a 3D supramolecular network containing large channels, in which the templated [H3N(CH2)6NH3]2+ cations are located.  相似文献   

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