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1.
Two original compounds, Ln4?2xBa2+2xZn2?xO10?2x, were isolated for Ln = La, Nd and 0 ≤ x ≤ 0.25. These oxides are tetragonal with a and c parameters close to 6.91 and 11.59 Å, respectively, for lanthanum, and 6.75 and 11.54 Å for neodymium. The structure of these phases was determined from X-ray powder patterns in the most symmetric space group, , using Patterson and Fourier functions for x = 0. The structure should be compared to that of copper oxides La4?2xBa2+2xCu2?xO10?2x: it is built up of identical Ln2O5 layers formed from face- and edge-sharing LnO8 polyhedra, between which Ba2+ and Zn2+ ions are inserted. Contrary to the copper compounds, two successive Ln2O5 layers are rotated by 90°, involving a doubling of c. The result for Zn2+ is tetrahedral coordination, while the coordination of Ba2+ becomes a bicapped antiprism. 相似文献
2.
About Ba10Fe8Pt2Cl2O25 The crystal structure of Ba10Fe8Pt2Cl2O25 has been solved by direct methods, using intensity data collected by means of an automatic diffractometer (MoKα). It crystallizes in the hexagonal space group D–P63/mmc: a = 5.8034(4) Å, c = 24.997(5) Å, Z = 1. Fe3+ ions occur in both octahedral and tetrahedral coordination. Two types of Ba2+ ions are formed, with ten and twelve neighbouring atoms. The structure consists of plane connected FeO6 and PtO6 octahedra which are connected by corner shared FeO4 tetrahedra. 相似文献
3.
Synthesis and Crystal Structure of Ba25Cu142+Cu43+Zn4O49 Single crystals of Ba25Cu142+Cu43+Zn4O49 were prepared with solid state and flux reactions. X-ray investigations show tetragonal symmetry, space group D74th–P4/nmm, a = 18.2146, c = 9.3230 Å, Z = 2. The hitherto unknown structure type shows copper in square pyramids and planar polygones, connected to six member rings or Cu5O20 groups. Slightly bent Cu5O12 groups produced by edge connection of five CuO4 polygones are connected with ZnO4 tetrahedra forming Cu5Zn4O20 units. The complicated structure is shown step by step. 相似文献
4.
A series of zinc oxides Ln2BaZnO5 has been synthesized for Ln = Sm, Eu, Gd, Dy, Ho, and Y. Theses phases are orthorhombic and isostructural with the copper compounds Ln2BaCuO5 previously described, as shown from the structural study of one member Y2BaZnO5. In this structure, whose framework is built up from edge- and face-sharing LnO7 polyhedra, the Zn2+ ions exhibit an unusual pyramidal coordination ZnO5. The solid solution Y2BaZn1?xCuxO5 has been studied by infrared spectroscopy and electron spin resonance (ESR). The distorted square-based pyramidal configuration of Zn2+ and Cu2+ is confirmed. The ESR spectra of diluted samples exhibit a hyperfine structure and are typical of individual Cu(II) ions. For higher Cu(II) contents, they exhibit an anisotropic broad signal which is interpreted in terms of CuCu interactions. 相似文献
5.
A Contribution on Ba3Pt4HgO11: The First Alkaline-Earth Oxoplatinate(II,V)/Oxomercurate Single crystals of Ba3Pt4HgO11 were prepared by oxygen high pressure technique (4 200–3 600 bar) and investigated by X-ray methods. It crystallizes with hexagonal symmetry, space group D? P6 2c, a = 6.021, c = 17.374 Å, Z = 2. Ba3Pt4HgO11 represents a new structure type, showing structural relationships to Ba2Hg3Pd7O14 and to the precious metal 6L-perovskites. The Hg2+ ions show dumb-bell like coordination, Pt2+ a square-planar surrounding and Pt5+ face shared double octahedra. 相似文献
6.
On the Synthesis and Crystal Structure of Ba6Lu4Zn10O22 with [OBa6] Octahedra Single crystals of Ba6Lu4Zn10O22 have been prepared by high temperature reactions and investigated by X-ray techniques. This compound is isotypic to Ba3In2Zn5O11 and the first member of the Rare Earth elements. Ba6Lu4Zn10O22 crystallizes with cubic symmetry, space group T-F4 3m, a = 13.452(1) Å and Z = 4. Zn2+ shows a tetrahedral, Lu3+ an octahedral and Ba2+ a three-fold capped trigonal prismatic coordination by O2?. The ZnO4 tetrahedra and LuO6 octahedra are forming macro polyhedra of the type Zn10O20 and Lu4O16. A discussion is given for the Ba6O33 and Ba6O42 groups. 相似文献
7.
Crystallographic studies of the Ba–Pt–O system have been undertaken using X-ray and electron diffraction techniques. The system is described by means of a Bap(BaxPt2+1−x)Pt4+p−2O3p−3formula which corresponds to a BaO3hexagonal based framework with Pt chains, whereprepresents the oxygen deficiency and the presence of both Pt4+and Pt2+cations in the compounds, andxa possible substitution of Pt2+by Ba2+in trigonal prismatic sites. The structure of a Ba4(Ba0.04Pt2+0.96)Pt4+2O9crystal has been solved by using 5548 X-ray difraction reflections collected on a twinned crystal. Refinements were performed with two distinct models: an “average”P321 space group and an “orthorhombic”C2 space group with cell parametersa=17.460(4) Å,b=10.085(2) Å,c=8.614(3) Å. In this structure, two Pt4+and one Pt2+cations are distributed over four Ba planes and form chains along thecaxis, consisting of two face-sharing Pt4+O6octahedra connected with one Pt2+O6trigonal prism. A lattice misfit occurs between the rigid barium lattice and the PtO3chains, giving rise to a composite structure. Twinning and domain configurations are described and taken into account in the refinement. This twinning is related to the presence of Pt2+cations, whose positions break the threefold axis symmetry. A diffraction anomalous fine structure (DAFS) study was also performed on this twinned single crystal. Anomalous scattering factorsf′ andf″ for platinum in this crystal were refined near the LIIIPt absorption edge. They confirm the weak barium occupancy of the trigonal prismataic site and the Pt4+valence of the octahedral sites. Reflection overlaps, due to twinning, flatten the DAFS sensitivity to Pt atoms in the prismatic sites and did not allow their clear valence determination, but Pt–O bond lengths agree with the presence of Pt2+cations at the center of prismatic faces. Electron diffraction patterns of powders having slightly different composition show a continuous evolution of incommensurate Bragg peaks and a weak correlation between the PtO3chains. They also confirm the composite nature and the one-dimensionality of the Bap(BaxPt2+1−x)Pt4+p−2O3p−3series, which can produce highly anisotropic physical properties. 相似文献
8.
Catherine Renard Pascal Roussel Annick Rubbens Sylvie Daviero-Minaud Francis Abraham 《Journal of solid state chemistry》2006,179(7):2101-2110
We report the synthesis and crystal structure of the new compound Sr4PbPt4O11, containing platinum in highly unusual square pyramidal coordination. The crystals were obtained in molten lead oxide. The structure was solved by X-ray single crystal diffraction techniques on a twinned sample, the final R factors are R=0.0260 and wR=0.0262. The symmetry is triclinic, space group P1¯, with , , , α=90.421(3)°, β=89.773(8)°, γ=90.140(9)° and Z=2. The structure is built from dumbell-shaped Pt2O9 entities formed by a dinuclear metal-metal bonded Pt26+ ion with asymmetric environments of the two Pt atoms, classical PtO4 square plane and unusual PtO5 square pyramid. Successive Pt2O9 entities deduced from 90° rotations are connected through the oxygens of the PtO4 basal squares to form [Pt4O108−]∞ columns further connected through Pb2+ and Sr2+ ions. Raman spectroscopy confirmed the peculiar platinum coordination environment. 相似文献
9.
On the Crystal Chemistry of a New Barium Rare-Earth Oxozincate: Ba2Er2Zn8O13 High temperature reactions led to single crystals of Ba2Er2Zn8O13. It crystallizes with orthorhombic symmetry, space group C122v? Cmc21, a = 6.276, b = 10.871, c = 10.195 Å, Z = 2. The hitherto unknown crystal structure shows Zn2+ with tetrahedral, Er3+ octahedral and Ba2+ cuboctahedral coordination by O2?. It will be shown that parts of the [Zn8O13] network are fragments of the ZnO structure showing O2? within a tetrahedral zinc coordination. A deficit of two O2? ions per unit cell is focused on two point positions. 相似文献
10.
Paul S. Haradem Bertrand L. Chamberland Lewis Katz Alain Gleizes 《Journal of solid state chemistry》1977,21(3):217-223
A single crystal study of Ba3Pt2O7 shows that the structure tolerates a variable composition which can be written Ba3Pt2+xO7+2x. The crystal studied has a hexagonal cell of dimensions a = 10.108 ± 0.006 Å and c = 8.638 ± 0.009 Å, and a probable space group . The density determined by water displacement is 7.99 g/cm3; the theoretical density for Ba3Pt2O7 is 7.94 g/cm3. The structure was determined from the set of 401 observed independent reflections obtained from 5189 reflections measured by automated counter methods. Refinement on F was carried to a conventional R of 8.0%. The structure has barium-oxygen layers with an essentially four-layer stacking sequence of the double hexagonal (ABAB) type. Platinum is found mainly in face-sharing octahedra, but is also distributed over some sites in which the coordination is nearly square planar and other sites in which the coordination is trigonal prismatic with three PtO bond lengths of 2.00 Å and three long PtO distances of 2.65 Å. The platinum with planar coordination is 0.08 Å from the plane of the four oxygen atoms. 相似文献
11.
Isolated Square-Planar Coordinated Pt2+ Inside of BaNd2PtO5 Single crystals of the hitherto unknown compound BaNd2PtO5 were prepared and examined by X-ray technique. The compound crystallizes with tetragonal symmetry D? P4 b2; a = 6.7569(6) and c = 5.9119(13) Å; Z = 2. The structure is discussed in respect of the isolated square-planare coordination of Pt2+ ions and its relation with other planar coordinated platinum of oxocompounds. 相似文献
12.
Hanskarl Müller‐Buschbaum Prof. Dr. 《无机化学与普通化学杂志》2007,633(15):2491-2522
On the Crystal Chemistry of Oxorhenates The review deals with the crystal chemistry of oxorhenates. In contrast to the crystal chemistry of the lately discussed rhodium oxides rhenium shows many and diverse coordination. Examples are square planar polygons, trigonal bipyramids and tetrahedral as well as octahedral surroundings by oxygen. Starting with the oxides ReO2, Re2O7, Re1,16O3, Re3O10 and ReO3 it will be shown that oxorhenates form isolated tetrahedra, octahedra, Re2O10‐ and Re2O9‐groups. The polyhedra of rhenium are isolated to each other or arranged in one‐dimensional chains, in two dimensional nets and three‐dimensional networks. Rhenium adapts the crystal structures of perowskites, fluorites, pyrochlores, rutiles and stacking variants of the perowskites. Special features are mercuro‐oxorhenates (HgReO4, Hg2ReO5, Hg5Re2O10) showing – Hg+‐Hg+ – groups and Rare Earth‐Oxorhenates (Ln2ReO5, Ln3Re2O9, Ln5Re2O12) revealing clearly visible Re‐Re – interactions. PbRe2O8 and BiReO4 are remarkable because of one sided open polyhedra, due to the lone pair activity. The positions of lone pairs (e2? – point charge) are verified by calculations of Madelung parts of lattice energy. 相似文献
13.
On the Crystal Structure of Ba3In2Zn5O11. An Oxoindate/zincatesol;zincate with Zn10O20 and In4O16 Macropolyhedra with Zn2+ in Tetrahedral Coordination by O2? Ba3In2Zn5O11 was prepared for the first time by a flux technique and investigated by single crystal X-ray work. It crystallizes with cubic symmetry, space group T-F4 3m, a = 13.3588 Å, Z = 8. Zn2+ show tetrahedral coordination by O2?, forming Zn10O20 macropolyhedra. In addition the nZn/Osol;O part of the crystal structure is made up of Zn10O20 parts. Edge connection of four InO6 octahedra results in In4O16 groups. The crystal structure will be shown and discussed. 相似文献
14.
On the Oxoargentato(I)-aurat(III): Ba4AgAuO6 The hitherto unknown compound Ba4AgAuO6 was prepared by oxidizing Ba/Au/Ag alloy with BaO2/Ba(OH)2 mixture in closed Ag tubes. X-ray single crystal investigation led to orthorhombic symmetry space group D-Cmcm; a = 13.275; b = 5.782; c = 11.396 Å; Z = 4. Ba4AgAuO6 shows distorted pentagonal bipyramidal polyhedra around Ba2+ and square planar AuO4 polygones. Ag+ shows an unusual 2 + 2 coordination by O2?. 相似文献
15.
A Contribution on CuPrMo2O8 and CuTbMo2O8 Single crystals of (I): CuPrMo2O8 and (II): CuTbMo2O8 were prepared by solid state reactions in closed copper tubes. They crystallize with orthorhombic symmetry, space group D-Pbca, (I): a = 10.4114, b = 9.8917, c = 14.8287 Å, (II): a = 10.2243, b = 9.7385, c = 14.6000, Z = 8. Both compounds are isotypic to CuYMo2O8, showing isolated MoO4 tetrahedra, square antiprismatic coordination of Ln3+ and Cu+ besides one edge of an O2? triangle. Calculations of the coulombterm of lattice energy support the oxidation state Cu2+ in combination with mixed valences of Mo6+ and Mo5+ on the molybdenum point positions. 相似文献
16.
New Compounds with Zinc in Square Pyramidal Coordination: BaZnDy2O5 and Ba1.25ZnHo2O5.25 (Ba5Zn4Ho8O21). Single crystals of (I): BaZnDy2O5 and (II): Ba5Zn4Ho8O21 were prepared by high temperature reactions and investigated by X-ray technique. (I) belongs to the BaCuLn2O5 type, space group D-Pbnm; a = 7.084; b = 12.368; c = 5.728 Å, Z = 4. (II) is isotypic to Ba5Mn4Ln8O21, space group C-I4/m; a = 13.779; c = 5.707 Å, Z = 2. The two different structure types are caused by the small difference in the composition of 0.25 BaO. Analogies and differences will be discussed. In addition the lattice constants of powder samples of Ba5Zn4Ln8O21 (Ln = Eu, Gd, Dy, Ho, Er and Y) are given. 相似文献
17.
A new Alkaline-Alkaline-Earth-Copper-Oxovanadate: Kba3Ca4Cu3V7O28 . Single crystals of Kba3Ca4Cu3V7O28 were prepared by solid state reactions below the melting point of the reaction mixture. It crystallizes with hexagonal symmetry, space group C?P63mc, a=11.160, c=12.428 Å, Z=2. Kba3Ca4Cu3V7O28 represents a new structure type with special coordination polyhedra around Ba2+, trigonal prisms and octahedra around Ca2+ and Cu2+ inside square pyramids. The crystal structure will be shown and discussed. 相似文献
18.
O. C. Saxena 《Mikrochimica acta》1968,56(2):448-451
Summary Direct titrimetric method for the estimation of uranium(VI) in the range of 0.7 to 76 mg is performed by decomposing and oxidising the complex, {U(VI)O2 · U(V)O2 · Fe(CN)6}, with ceric sulphate. The mixed valency state in the above mentioned complex has been confirmed by magnetic measurements, the isolated complex being paramagnetic. Na+, K+, Cs+, Ca2+, Sr2+, Mg2+, Be2+, Pd2+, La3+, Ir3+, Ru3+, and Te4+ do not interfere but Ag+, Tl+, Cu2+, Ba2+, CO2+, Ni2+, Zn2+, Pb2+, Hg2+, Sn2+, Bi3+, Au3+, Rh3+, Sb3+, In3+, Ti3+, Th4+, Zr4+, Pt4+, V5+, Se6+, MO6+, and Os8+ do.
Zusammenfassung Die Bestimmung von Uran(VI) in der Größenordnung von 0,7 bis 76 mg erfolgt durch Zersetzung und Oxydation des Komplexes U(VI)O2 · U(V)O2 · · Fe(CN)6 mit Cer(IV) sulfat. Die zweierlei Wertigkeitsstufen in diesem paramagnetischen Komplex wurden durch magnetische Messungen bestätigt. Na+, K+, Cs+, Ca2+, Sr2+, Mg2+, Be2+, Pd2+, La3+, Ir3+, Ru3+, and Te4+ stören nicht; hingegen stören Ag+, Tl+, Cu2+,Ba 2+, CO2+, Ni2+, Zn2+, Pb2+, Hg2+, Sn2+, Bi3+, Au3+, Rh3+, Sb3+, In3+, Ti3+, Th4+, Zr4+, Pt4+, V5+, Se6+, MO6+, and Os8+.相似文献
19.
On Osocuprates. XI. Ba3Cu2O4Cl2 A new oxohalogenocuprat, Ba3Cu2O4Cl2 mas prepared and investigated by X-ray single crystal methods. The hitherto unknown compound has orthorhombic symmetry (Space group: D2h5—Pmma; a = 6.653, b = 6.000, c = 10.563 Å). It shows angled chains of O2?-squares around Cu2+. One of the Cu2+ positions is completed by Clminus; to a tetragonal pyramid. The coordination polyhedrals of BaI–III and the connection with the Cu/O-chains are described and discussed. 相似文献
20.
Jovica Stojanovi Tamara ?or?evi Ljiljana Karanovi 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(11):i91-i94
During an investigation of the insufficiently known system M1O–M2O–X2O5–H2O (M1 = Cd2+, Sr2+ and Ba2+; M2 = Cu2+, Ni2+, Co2+, Zn2+ and Mg2+; X = P5+, As5+ and V5+), single crystals of the novel compound dicadmium copper(II) bis[phosphate(V)], Cd2Cu(PO4)2, were obtained. This compound belongs to a small group of compounds adopting a Cu3(PO4)2‐type structure and having the general formula M12M2(XO4)2 (M1/M2 = Cd2+, Cu2+, Mg2+ and Zn2+; X = As5+, P5+ and V5+). The crystal structure is characterized by the interconnection of infinite [Cu(PO4)2]n chains and [Cd2O10]n double chains, both extending along the a axis. Exceptional characteristics of this structure are its novel chemical composition and the occurrence of double chains of CdO6 polyhedra that were not found in related structures. In contrast to the isomorphous compounds, where the M1 cations are coordinated by five O atoms, the Cd atom is coordinated by six. The dissimilarity in the geometry of M1 coordination between Cd2Cu(PO4)2 and the isomorphous compounds is mostly due to the larger ionic radius of the Cd cation in comparison with the Cu, Mg and Zn cations. Sharing a common edge, two CdO6 polyhedra form Cd2O10 dimers. Each such dimer is bonded to another dimer sharing common vertices, forming [Cd2O10]n double chains in the [100] direction. The Cu atoms, located on an inversion centre (site symmetry ), form isolated CuO4 squares interconnected by PO4 tetrahedra, forming [Cu(PO4)2]n chains similar to those found in related structures. Conversely, the [Cd2O10]n double chains, which were not found in related structures, are an exclusive feature of this structure. 相似文献