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1.
The previously unknown crystal structure of strontium magnesium phosphate, Sr2+xMg3−xP4O15 (x∼ 0.36), determined and refined from laboratory powder X‐ray diffraction data, represents a new structure type. The title compound was synthesized by high‐temperature solid‐state reaction and it crystallizes in the orthorhombic space group Cmcm. It was earlier thought to be stoichiometric Sr2Mg3P4O15, but our structural study indicates the nonstoichiometric composition. The asymmetric unit contains one Sr (site symmetry ..m on special position 8g), one M (= Mg 64%/Sr 36%; site symmetry 2/m.. on special position 4b), one Mg (site symmetry 2.. on special position 8e), two P (site symmetry m.. on special position 8f and site symmetry ..m on special position 8g), and six O sites [two on general positions 16h, two on 8g, one on 8f and one on special position 4c (site symmetry m2m)]. The nonstoichiometry is due to the mixing of magnesium and strontium ions on the M site. The structure consists of three‐dimensional networks of MgO4 and PO4 tetrahedra, and MO6 octahedra with the other strontium ions occupying the larger cavities surrounded by ten O atoms. All the polyhedra are connected by corner‐sharing except the edge‐sharing MO6 octahedra forming one‐dimensional arrangements along [001].  相似文献   

2.
The system CuO‐NiO‐P4O10 was investigated using a solid state reaction between CuO, NiO, and (NH4)2HPO4 in quartz crucibles at 900 °C. The powder samples were characterized by X‐ray diffraction, TG/DTA, electrochemical measurements, IR, and UV/Vis spectroscopy. Single crystals of a new quaternary phase Cu3NiO(PO4)2 were achieved by cooling the melted compound in a sealed, evacuated quartz ampoule. Cu3NiO(PO4)2 crystallizes in the monoclinic space group P21/n (no 14) with a = 8.2288(2) Å, b = 9.8773(2) Å, c = 8.2777(3) Å, β = 107.82(2)°, Z = 4. The three‐dimensional framework consists of distorted tetragonal pyramides [Cu1O5], distorted planar squares [Cu2O4], octahedra [Cu3O6], and [NiO6] and [PO4] tetrahedra. The TG‐DTA of the new phase showed an incongruent melting at 1055 °C. The open circuit voltage of this material was measured to determine the electrochemical properties. The measurement revealed an initial capacity of 236 Ah · g–1 and a voltage plateau at 2.05 V. Furthermore, it was possible to identify the phase equilibria and to obtain the phase diagram at 900 °C.  相似文献   

3.
The system CuO‐Fe2O3‐P2O5 has been investigated by means of the solid state reaction between CuO, Fe2O3 and (NH4)2HPO4 in quartz crucibles at 900 °C. The powder samples were characterized by X‐ray diffraction, IR spectroscopy and TG/DTA. Single crystals of a new quaternary phase Cu8Fe2P4O21 were achieved by cooling from the melt of the compound in a sealed, evacuated quartz ampoule. Cu8Fe2O5(PO4)4 crystallizes in the monoclinic space group C2/m (No 12) with a = 15.9733(8) Å, b = 5.9438(3) Å, c = 9.5530(5) Å, β = 113.76(1)°, Z = 2. The three‐dimensional framework consists of [FeO6] octahedra, three different [CuO5] polyhedra and [PO4] tetrahedra. Cu8Fe2P4O21 exhibits an incongruently melting point at 945 °C.  相似文献   

4.
Cd2Cu(PO4)2     
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   

5.
Cu4O12 Groups Built of Square Planar CuO4 Polygones in the Barium Vanadyl Oxocuprate(II) Phosphate Ba(VO)Cu4(PO4)4 Single crystals of Ba(VO)Cu4(PO4)4 have been prepared by solid state reactions just below the melting points of the reaction mixtures of BaP2O6, Cu3(PO4)2, CuO, V2O5 and V2O3 in evacuated closed quartz glas tubes. The compound crystallizes with tetragonal symmetry, Space group D? P4212, a = 9.560(2), c = 7.160(2) Å, Z = 2. Special and new features of the crystal structure are to each other isolated Cu4O12 and (VO)(PO4)4 groups. The crystal chemistry of the Cu4O12 groups is discussed with respect to other compounds containing out of plane connected square planar MO4 polygones.  相似文献   

6.
Three new copper 4-carboxyphenylphosphonates with formulae Cu(HOOCC6H4PO3)·2H2O, Cu(HOOCC6H4PO3) and Cu3(OOCC6H4PO3)2·3H2O were prepared and characterized by thermogravimetric analysis, X-ray diffraction analysis, energy-dispersive X-ray microanalysis and infrared spectroscopy. The preparation conditions of Cu(HOOCC6H4PO3)·2H2O and Cu3(OOCC6H4PO3)2·3H2O differ in the acidity of the reaction mixture, where Cu(HOOCC6H4PO3) was prepared under hydrothermal conditions. Copper 4-carboxyphenylphosphonate with formula Cu3(OOCC6H4PO3)2·3H2O reacts with 4-carboxyphenylphosphonic acid to form Cu(HOOCC6H4PO3)·2H2O.Cu(HOOCC6H4PO3)·2H2O is orthorhombic, space group Pbcn (no. 60), a=8.234(2) Å, b=9.438(2) Å, c=24.899(5) Å. Cu(HOOCC6H4PO3) crystallizes in the monoclinic space group P21/c (no. 14), a=19.0951(3), b=8.0968(4), c=5.2111(11) Å, β=94.914(6)°, Z=4. Its layered structure is composed of distorted CuO6 octahedra arranged hexagonally in a gibbsite-like manner around two phosphonate groups, which have their carboxyphenyl groups extending into the space above and below the copper–phosphonate layer. Infrared spectra indicate that for both Cu(HOOCC6H4PO3)·2H2O and Cu(HOOCC6H4PO3) the acid hydrogen is present at the carboxyl group and not at the phosphonic group.  相似文献   

7.
Contributions on Crystal Chemistry and Thermal Behaviour of Anhydrous Phosphates. XXIV. Preparation, Crystal Structure, and Properties of Copper(II) Indium(III) Orthophosphate Cu3In2[PO4]4 Crystals of Cu3In2[PO4]4 were grown by chemical vapour transport (temperature gradient 1273 K → 1173 K) using chlorine as transport agent. The mixed metal phosphate forms a new structure type (P21/c, Z = 2, a = 8.9067(6), b = 8.8271(5), c = 7.8815(5) Å, β = 108.393(5)°, 13 atoms in asymmetric unit, 2549 unique reflections with Fo > 4σ, 116 variables, R(F2) = 0.065). The crystal structure shows a hexagonal closest packing of [PO4]3– tetrahedra. Close‐packed layers parallel (1 0 –1) are stacked according to the sequence A, B, A′, B′, A. The octahedral interstices in this packing are completely occupied by two In3+, one (Cu1)2+ and a “dumb bell” (Cu2)24+. In the latter case four of the six phosphate groups that belong to this octahedral void act as bi‐dentate ligands, thus forming dimers [(Cu2)2O10] with dCu–Cu = 3.032 Å. Cu3In2[PO4]4 is paramagnetic (μeff = 1.89 μB, θP = –16.9 K). The infrared and UV/Vis reflectance spectra are reported. The observed d‐electron levels of the Cu2+ cations agree well with those obtained from angular overlap calculations.  相似文献   

8.
Uranyl vanadate compounds with divalent cations, M(UO2)(V2O7) (M = Ca, Sr) and Sr3(UO2)(V2O7)2, were synthesized by flux crystal growth, and their crystal structures were solved using single‐crystal X‐ray diffraction data. Ca(UO2)V2O7 and Sr(UO2)V2O7 were synthesized from reactants with molar ratios M:U:V of 1:1:2 and identical heating conditions, and increasing the M:U:V ratio to 3:1:4 resulted in Sr3(UO2)(V2O7)2. Crystallographic data for M(UO2)V2O7 compounds are: a = 7.1774(18) Å, b = 6.7753(17) Å, c = 8.308(2) Å; V = 404.01(18) Å3; space group Pmn21, Z = 2 for Ca; a = 13.4816(11) Å, b = 7.3218(6) Å, c = 8.4886(7) Å; V = 837.91(12) Å3; space group Pnma, Z = 4 for Sr. Compound Sr3(UO2)(V2O7)2 has a = 6.891(3) Å, b = 7.171(3) Å, c = 14.696(6) Å, α = 85.201(4)?, β = 78.003(4)?, γ = 89.188(4)?; V = 707.9(5) Å3; space group P1 , Z = 2. The framework structure of Sr(UO2)(V2O7) is related to that of Pb(UO2)(V2O7) reported previously, while that of Ca(UO2)(V2O7) has a different topology. The topological polymorphism of the [(UO2)(V2O7)]‐type framework may be due to the differing ionic radii of the guest M2+ cations. Compound Sr3(UO2)(V2O7)2 has a modular structure based on two different types of electroneutral layers: [Sr(UO2)(V2O7)] and [Sr2(V2O7)]. Structural complexities were calculated, and Raman spectra were collected and their peaks were assigned.  相似文献   

9.
The Copper(II) Oxide Phosphate Cu4O(PO4)2 in a New, Orthorhombic Modification by Oxidation of a Tl/Cu/P Alloy Single crystals of Cu4O(PO4)2 in a new, orthorhombic modification were prepared by reaction of a Tl/Cu/P alloy with oxygen. The compound crystallizes in the space group Pnma with Z = 4 and lattice constants a = 808.8(5) pm, b = 627.0(7) pm, c = 1338.3(1) pm. It is isotypic with the orthorhombic form of Cu4O(AsO4)2. The copper atoms are five-coordinated by oxygen. The distorted square-pyramidal and trigonal-bipyramidal polyhedra are connected by edges and vertices to form [Cu8O18] ribbons running along [010] and forming slabs perpendicular to the c-axis interconnected by phosphate groups.  相似文献   

10.
Contributions on the Thermal Behaviour and Crystal Chemistry of Anhydrous Phosphates. XXXIX, Syntheses, Crystal Structures and Structural Systematics of Quaternary Vanadium(IV) Oxidephosphates MIIV2O2(PO4)2 (MII: Co, Ni, Cu) By vapour‐phase assisted solid state reactions single‐crystals of the oxidephosphates α‐CoV2O2(PO4)2 (green), β‐NiV2O2(PO4)2 (yellow), and CuV2O2(PO4)2 (brown) suitable for structural investigations were grown ( α‐CoV2O2(PO4)2 : P21/c, Z = 2, a = 6.310(1), b = 7.275(1), c = 7.441(2) Å, β = 90.30(2)°, R1 = 0.044, wR2 = 0.083, 1515 independent reflections, 71 variables; β‐NiV2O2(PO4)2 : P21/c, Z = 2, a = 7.4013, b = 7.2595, c = 7.4230Å, β = 121.56°, R1 = 0.037, wR2 = 0.084, 1117 independent reflections, 61 variables; CuV2O2(PO4)2 : Pbca, Z = 8, a = 7.352(1), b = 12.652(1), c = 14.504(2) Å, R1 = 0.048, wR2 = 0.067, 2886 independent reflections, 136 variables). β‐CoV2O2(PO4)2 and α‐NiV2O2(PO4)2 were obtained as powders only. The α‐forms belong to the α‐Fe2O(PO4) structure family, while the β‐forms are isotypic to NiTi2O2(PO4)2 (Lipscombite/Lazulite structure family). The oxidephosphate structures are characterized by three‐dimensional networks of [PO4] tetrahedra and [MV2O12] groups formed by face‐sharing of [MIIO6] and [VIVO6] octahedra.  相似文献   

11.
The reaction of CuCl2 · 2 H2O, 1,10‐phenanthroline (phen), suberic acid and Na2CO3 in a CH3CN–H2O solution yielded blue needle‐like crystals of [Cu2(phen)2(C8H12O4)2] · 3 H2O. The crystal structure (monoclinic, P21/n, a = 10.756(2) Å, b = 9.790(2) Å, c = 18.593(4) Å, β = 91.15(3)°, Z = 2, R = 0.043, wR2 = 0.1238) consists of suberato‐bridged [Cu2(phen)2(C8H12O4)4/2] layers and hydrogen bonded H2O molecules. The Cu atoms are coordinated by two N atoms from one bidentate chelating phen ligand and three carboxyl O atoms from different suberato ligands to form distorted [CuN2O3] square‐pyramids with one carboxyl O atom at the apical position (d(Cu–N) = 2.017(2), 2.043(3) Å, basal d(Cu–O) = 1.936(2), 1.951(2) Å and axial d(Cu–O) = 2.389(2) Å). Two [CuN2O3] square‐pyramids are condensed via a common O–O edge to a centrosymmetric [Cu2N4O4] dimer with the Cu…Cu distance of 3.406(1) Å indicating no interaction between Cu atoms. The resultant [Cu2N4O4] dimers are interlinked by the tridentate suberato ligands to form [Cu2(phen)2(C8H12O4)4/2] layers parallel to (101). These are assembled via π‐π stacking interactions into 3D network with H2O molecules in the tunnels extending in the [010] direction.  相似文献   

12.
The solid solution Sr2−xPbxV3O9, 0≤x≤2, was prepared by solid state reactions and characterized by X-ray diffraction, IR spectroscopy, and magnetic susceptibility measurements. Single crystals of the pure strontium phase and mixed Sr/Pb compounds were prepared by high temperature treatment of the respective powder compositions. Pb2V3O9crystals could only be obtained by the electrochemical reduction of molten PbV2O6. These crystals were always twinned. The previously reported crystal structure of Sr2V3O9was confirmed. It was refined toR=0.050,Rw=0.057, in space group C2/c,a=7.555(1) Å,b=16.275(2) Å,c=6.948(1) Å,β=119.78(1)°. The single crystal structural studies of the Sr1.02Pb0.98V3O9and Sr0.67Pb1.33V3O9members of the series show that the introduction of lead gives rise to a progressively complicated splitting of Sr2+/Pb2+and the tetrahedral vanadium ion crystallographic sites. As a consequence the vanadium framework distorts and beyond the Sr0.5Pb1.5V3O9composition the crystal symmetry becomes triclinic. This distortion is ascribed to the stereochemical effect of the 6s2lone pair of Pb2+. The crystallographic parameters of Pb2V3O9area=7.598(1) Å,b=16.393(3) Å,c=6.972(2) Å,α=91.38(1)°,β=119.35(1)°,γ=90.47(1)°. Pb2V3O9exhibits a more complex IR spectrum than the monoclinic phases. Despite the similarity between the triclinic and monoclinic phases the magnetic susceptibilities indicate differences in the coupling between V4+ions at low temperatures.  相似文献   

13.
This paper reports on synthesis and X-ray diffraction study of two groups of phases obtained from batch mixtures: (La,Sr k+1(Ru,Cu) k O3k+1 and (La,Sr)3(Ru,Cu)3O6+ (group I); RuSr2LnCu2O8– (Ln = Nd for the first time, Sm, Eu, Gd, (Gd,Y) for the first time), RuSr2(Ln,Ce4+)2Cu2O10– (Ln = Pr and Nd for the first time, Sm, Eu, Gd, (Gd,Y) for the first time), and (Ru,Cu)Sr2(Ln,Ce4+)2Cu2O10– (Ln = Tb and Y for the first time) (group II). In group I, phases with K2NiF4, Sr3Ti2O7, and cubic perovskite type structures are typically formed; in group II, these are respectively (Ru,Cu)(Sr,Ln)2(Ln,Sr)Cu2O8– (1212 type), (Ru,Cu)(Sr,Ln)2(Ln,Ce4+)2Cu2O10– (1222 type), and cubic perovskite type structures (the content of the latter depends on the type of Ln). Variation of the formal charge (f.c.) of Ru (group I) and Cu (group II) was evaluated in relation to the cation composition of the phases (groups I and II) and the content of superstoichiometric oxygen (group II). Phases of 1222 type with Ln = Nd, Sm, Eu, Gd, and (Gd,Y) and phases of 1212 type with Ln = Gd exhibited superconducting properties with T c max 40 K.  相似文献   

14.
A New Lead Strontium Ferrate(III): The Crystal Structure of the Phase Pb4Sr2Fe6O15 At orthorhombic single crystals of Pb4Sr2Fe6O15 (a = 568.73(8), b = 392.03(4), c = 2107.5(3) pm; Z = 4/3, space group Pnma) a X-ray structure determination has been performed (R1 = 0,036 for 488 ?observed”? resp. wR2 = 0,073 for all 643 independent reflexions). It revealed a framework of polyhedra related to perovskite, in which chains of edgesharing pyramids [FeO5] (average Fe1? O: 197 pm; Fe1? Fe1: 305.5 pm) are linked via apices with corner-sharing [FeO6] octahedra (Fe2? O: 201 pm). 12–fold, strongly distorted cuboctahedrally coordinated ?perovskite positions”? show mixed occupancy by 2/3 Sr + 1/3 Pb (= Sr2; Sr2? O: 287 pm). More spacy channels, running parallel to the chains of pyramids along [010] of the structure, contain lead atoms only. The double occupancy of the corresponding cages results in short distances Pb1? Pb1 (355.9 pm) and Pb1? Fe2 (314.4 pm), as well as in a very asymmetric [PbO6] coordination (Pb1? O: 253 pm), in the opposite hemisphere of which the lone electron pair s2 is supposed to be located. Details are communicated and structural relations discussed.  相似文献   

15.
Synthesis of Copper and Silver Complexes with Pentadentate N,S and Hexadentate N,O Chelate Ligands – Characterization and Crystal Structures of {Cu2[C6H4(SO2)NC(O)]2(C5H5N)4}, {Cu2[C5H3N(CHNC6H4SCH3)2]2}(PF6)2, and {Ag[C5H3N(CHNC6H4SCH3)2]}PO2F2 In the course of the reaction of copper(II)-acetate monohydrate with 2,2′-bisbenzo[d][1,3]thiazolidyl in methanol the organic component is transformed to N,N′-bis-(2-thiophenyl)ethanediimine and subsequently oxidized to the N,N′-bis-(2-benzenesulfonyl)ethanediaciddiamide H4BBSED, which coordinates in its deprotonated form two Cu2+ ions. Crystallisation from pyridine/n-hexane yields [Cu2(BBSED)(py)4] · MeOH. It forms triclinic crystals with the space group P1 and a = 995.5(2) pm, b = 1076.1(3) pm, c = 1120.7(2) pm, α = 104.17(1)°, β = 105.28(1)°, γ = 113.10(1)° and Z = 1. In the centrosymmetrical dinuclear complex the copper ions are coordinated in a square-pyramidal arrangement by three nitrogen and two oxygen atoms. The Jahn-Teller effect causes an elongation of the axial bond by approximately 30 pm. The reactions of the pentadentate ligand 2,6-Bis-[(2- methylthiophenyl)-2-azaethenyl]pyridine BMTEP with salts of copper(I), copper(II) and silver(I) yield the complexes [CU2(BMTEP)2](PF6)2, [Cu(BMTEP)]X2 (X = BF, C1O) and [Ag(BMTEP)]X (X = PO2F, ClO). [Cu2(BMTEP)2](PF6)2 crystallizes from acetone/diisopropyl- ether in form of monoclinic crystals with the space group C2/c, and a = 1833.2(3) pm, b = 2267.30(14) pm, c = 1323.5(2) pm, β= 118.286(5)°, and 2 = 4. In the dinuclear complex cation with the symmetry C2 the copper ions are tetrahedrally coordinated by two bridging BMTEP ligands. The Cu? Cu distance of 278.3pm can be interpreted with weak Cu? Cu interactions which also manifest itself in a temperature independent paramagnetism of 0.45 B.M. The monomeric silver complex [Ag(BMTEP)]PO2F2 crystallizes from acetone/thf in the triclinic space group P1 with a = 768.7(3) pm, b = 1074.0(5) pm, c = 1356.8(5) pm, α = 99.52(2)°, β = 96.83(2)°, γ = 99.83(2)° and Z = 2. The central silver ion is coordinated by one sulfur and three nitrogen atoms of the ligand in a planar, semicircular arrangement. The bond lengths Ag? N = 240.4–261.7 and Ag? S = 257.2 pm are significantly elongated in comparison with single bonds.  相似文献   

16.
Single crystals of new quaternary compounds Sr8Cu3In4N5 and Sr0.53Ba0.47CuN were prepared, respectively, from a Sr–Cu–In–Na melt under 7 MPa of N2 and from a Sr–Ba–Cu–In–Na melt under 0.5 MPa of N2 by slow cooling from 1023 to 823 K. The crystal structures were determined by single-crystal X-ray diffraction. Sr8Cu3In4N5 has an orthorhombic structure (space group, Immm, Z=2, a=3.8161(5) Å, b=12.437(2) Å, c=18.902(2) Å), and is isostructural with Ba8Cu3In4N5. It contains nitridocuprates of isolated units 0[CuN2] and one-dimensional linear chains 1[CuN2/2] and one-dimensional indium clusters 1[In2In2/2]. Sr0.53Ba0.47CuN crystallizes in an orthorhombic cell, space group Pbcm, Z=4, a=5.4763(7) Å, b=9.2274(12) Å, c=9.0772(12) Å. The structure contains infinite zig-zag chains 1[CuN2/2] which kink at every second nitrogen atom.  相似文献   

17.
The blue copper complex compounds [Cu(phen)2(C6H8O4)] · 4.5 H2O ( 1 ) and [(Cu2(phen)2Cl2)(C6H8O4)] · 4 H2O ( 2 ) were synthesized from CuCl2, 1,10‐phenanthroline (phen) and adipic acid in CH3OH/H2O solutions. [Cu(phen)2‐ (C6H8O4)] complexes and hydrogen bonded H2O molecules form the crystal structure of ( 1 ) (P1 (no. 2), a = 10.086(2) Å, b = 11.470(2) Å, c = 16.523(3) Å, α = 99.80(1)°, β = 115.13(1)°, γ = 115.13(1)°, V = 1617.5(5) Å3, Z = 2). The Cu atoms are square‐pyramidally coordinated by four N atoms of the phen ligands and one O atom of the adipate anion (d(Cu–O) = 1.989 Å, d(Cu–N) = 2.032–2.040 Å, axial d(Cu–N) = 2.235 Å). π‐π stacking interactions between phen ligands are responsible for the formation of supramolecular assemblies of [Cu(phen)2(C6H8O4)] complex molecules into 1 D chains along [111]. The crystal structure of ( 2 ) shows polymeric [(Cu2(phen)2Cl2)(C6H8O4)2/2] chains (P1 (no. 2), a = 7.013(1) Å, b = 10.376(1) Å, c = 11.372(3) Å, α = 73.64(1)°, β = 78.15(2)°, γ = 81.44(1)°, V = 773.5(2) Å3, Z = 1). The Cu atoms are fivefold coordinated by two Cl atoms, two N atoms of phen ligands and one O atom of the adipate anion, forming [CuCl2N2O] square pyramids with an axial Cl atom (d(Cu–O) = 1.958 Å, d(Cu–N) = 2.017–2.033 Å, d(Cu–Cl) = 2.281 Å; axial d(Cu–Cl) = 2.724 Å). Two square pyramids are condensed via the common Cl–Cl edge to centrosymmetric [Cu2Cl2N4O2] dimers, which are connected via the adipate anions to form the [(Cu2(phen)2Cl2)(C6H8O4)2/2] chains. The supramolecular 3 D network results from π‐π stacking interactions between the chains. H2O molecules are located in tunnels.  相似文献   

18.
Strontium phosphate apatites containing different amounts of copper were prepared by a solid state reaction at 1100 °C or by arc melting above 1600 °C in air. The samples were characterized by X‐ray diffraction, ICP analysis, scanning electron microscopy, IR spectroscopy, MAS—1H—NMR, diffuse reflectance spectroscopy, and SQUID magnetometry. X‐ray crystal structure determination was carried out for a single crystal obtained from the melt. The compound is formulated as Sr5(PO4)3(CuO2)1/3 and has an apatite structure (space group P63/m, a = 9.7815(4)Å, c = 7.3018(4)Å, Z = 2) with linear CuO23— ions occupying hexagonal channels. For solid state synthesized samples, Rietveld refinement of powder XRD patterns was performed. The samples obtained at 1100 °C acquire the composition Sr5(PO4)3CuxOHy, with x changing from 0.01 to 0.62 and y < 1—x. The copper content can be increased to x = 0.85 by annealing in argon at 950 °C. The compounds represent a hydroxyapatite in which part of the protons is substituted by Cu+ and Cu2+ ions. The ions form linear O—Cu—O units which are progressively condensed creating the Cu—O—Cu bridges on increasing copper content. IR and NMR data testify existence of OH groups, non‐disturbed and disturbed by neighboring Cu atoms. In the electron spectra, the samples exhibit absorption bands at 7800‐7900, 14200‐14500 and 17500‐17550 cm—1, which were assigned to Cu2+ d‐electron transitions. By annealing the sample with x = 0.1 in oxygen at 800 °C copper is fully oxidized while retaining in channels in unusual for Cu2+ linear coordination.  相似文献   

19.
Tl2CuAsO4 – an Intermediate Phase in the Oxidation of Tl/Cu/As Alloys with Oxygen Waxy, honey-jellow single crystals of the new compound Tl2CuAsO4 (monoclinic, P21/c, a = 860.1(1) pm, b = 533.94(7) pm, c = 1200.1(2) pm, β = 98.10(1)°, Z = 4) were prepared as an intermediate product of the oxidation process in the reaction of Tl/Cu/As-alloys with oxygen. Their structure was determined from IPDS data (w2R = 0.071 for 1271 F2 values and 74 parameters). The structure contains an isolated [Cu2As2O8]4– group consisting of two AsO4-tetrahedra connected by two Cu+ ions with an approximately linear O–Cu–O coordination. The [Cu2As2O8]4– groups are linked to a threedimensional framework by thallium(I) ions which show an hemispheric coordination sphere of oxygen ions indicating the stereochemical activity of the Tl+ lone pair.  相似文献   

20.
This paper reports on the refined compositions and crystal structures of two phases from the homologous series (Hg, M)(Sr, Pr)2(Pr, Sr)k-1CukO2k+2+ with k = 2 (Hg-1212) — (Hg0.44(2)Ce 0.31 4+ Cu0.25)(Sr0.90(3)Pr0.10)2(Pr0.52(3)Sr0.48)Cu2.00O7.00 (a = 3.8634(1), c = 12.2030(8) , space group P4/mmm) with k = 3 (Hg-1223) — (Hg0.29(1) )(Sr0.67(2)Pr0.33)2(Pr0.61(2)Sr0.39)2Cu3.00O9.32(8) or (Hg0.29(1) )(Sr0.61(4)Pr0.39)2(Pr0.51(4)Sr0.49)2Cu3.00O9.00 (with a fixed content of superstoichiometric oxygen O(4) in the phase) ( is a vacancy; a = 3.8294(9), b = 3.8567(6), c = 15.2763(44) , space group Pmmm). The implausibly high content of oxygen in the Hg-1223 phase (refinement I) is attributed either to O–O bond formation or to the possible presence of a minor amount of copper in a defect position of Hg; the inclusion of the latter in structure refinement leads to a better reproduction of the real structure but increases the R indices. The crystal-chemical analysis of the title phases and a comparison with the available data for analogous phases indicates that the composition of the crystallographic positions is related to structural features, in particular, to the coordinates of (Hg, M) and superstoichiometric oxygen, whose content depends on the degree of substitution of strontium ions by praseodymium ions. Reasons for the orthorhombic distortion of the Hg-1223 phase are discussed. The absence of superconductivity is explained by the nonoptimal formal charge (FC) of copper, which depends on the oxygen content in the phase.  相似文献   

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