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1.
The System Cs/Cu/F: On CsCuIICuIIIF6 ?CsCuF3,6’? is described in literature as a darkbrown powder which is supposed to crystallize in a cubic lattice (a = 882 pm, Debyeogramms). However Guinier photographs show that ?CsCuF3,6’? is a mixture of CsCuIICuIIIF6 (black, isotypic to CsNiIINiIIIF6, a = 706.7 b = 727.7, c = 1032.2 pm, Z = 4) and Cs2CuCuIIIF6 (auburn, pseudocubic, a = 623.4 c = 886.4 pm, Z = 2).  相似文献   

2.
The Crystal Structure of Perovskites A NiIIMVIO6. II. Sr2NiWO6 The results of an X-ray single crystal study of the perovskite Sr[NiIIWVI](6)O6, ordered in the octahedral sites, are given. While Sr[NiIITeVI](6)O6 crystallizes in a monoclinically deformed structure of the perovskite (elpasolite) type, showing a phase transition to a tetragonal lattice at 675 °K, Sr[NiIIWVI](6)O6 is tetragonal already at 298°K (space group: C; a = b = 5.559 Å; c = 7.918 Å; Z = 2). The Ni? O distances found for the tungsten compound are nearly identical with those of the tellurium perovskite. In contradiction to crystal field theory very different values of the ligand field parameter Δ (ca. 25%) are observed for these two compounds however. Obviously this effect is caused by the rather different kind of bonding within the NiO6 polyhedra in the two compounds. On the basis of the structural results the Ni? O-bonding in the two perovskites is discussed in dependence of the next nearest cationic environment.  相似文献   

3.
On Ordered Perovskites with Cationic Vacancies. X. Compounds of Type A B B □1/4MVIO6 ? A BIIB □M O24 with AII, BII = Ba, Sr, Ca and MVI = U, W Perovskites of type Ba8BIIB2III□UO24 show polymorphic phase transformations of order disorder type. An 1:1 ordered orthorhombic HT form is transformed into a higher ordered LT modification with a fourfold cell content (four formula units Ba8BIIB□U4O24), compared to cubic 1:1 ordered perovskites A2BMO6. In the series Ba8BaB□W4O24 and Sr8SrB□W4O24 different ordering phenomena are observed. In comparison with 1:1 ordered cubic perovskites A2BMO6, the cell contains eight formula units ABIIB□W4O24. The higher ordered cells with UVI and WVI are face centered, which has its origin in an ordering of cationic vacancies.  相似文献   

4.
Compounds in the Systems Potassium(Rubidium)/Gold/Antimony: K3Au3Sb2, Rb3Au3Sb2, and K1,74Rb0,26RbAu3Sb2 Brittle, silver coloured single crystals of K3Au3Sb2, Rb3Au3Sb2 and K1,74Rb0,26RbAu3Sb2 were obtainded by reaction of the alkali metal azides (KN3, RbN3) with gold and antimon powder at 550°C. The structures of the isotypic compounds (R3 m, Z = 3) were determined by X-ray single-crystal diffractometer data: K3Au3Sb2, a = 6,198(2) Å, c = 21,520(5) Å, R/Rw (w = 1) = 0,046/0,058, Z(F) ? 3σ(F) = 175, Z(Var.) = 14; Rb3Au3Sb2, a = 6,443(3), c = 21,69(2), R/Rw (w = 1) = 0,059/0,082, Z(F) ? 3σ(F02) = 258, Z(Var.) = 14; K1,74Rb0,26RbAu3Sb2, a = 6,288(2) Å, c = 21,617(5) Å, R/Rw (w = 1) = 0,049/0,069, Z(F) ? 3σ(F) = 390, Z(Var) = 14. The compounds crystallize with the K3Cu3P2-structure type. The Au? Sb partial structures consist of [AuSb2/3] layers with linear Sb? Au? Sb dumb-bells and SbAu3 pyramids. The layers are separated by two crystallographically independent alkali metal atoms along [001].  相似文献   

5.
On the Stoichiometry of the Allotropic Variation γ-Bi2O3 The study of the solid solutions Bi12[BBi□1/5]O20 (B+V = As, V) with 0 ? x ? 0,80 leads for x = 0,77 to a phase whose cubic centered symmetry and parameter (10.255 Å) correspond to those previously announced for γ-Bi2O3. The présence of impurities seems required to obtain such a phase whose theoretical stoichiometry should be Bi12[Bi□1/5]O20 i. e. Bi2O3,125.  相似文献   

6.
Pb7FeIIFeF34 is monoclinic: a = 16.375(2) Å, b = 11.233(2) Å, c = 7.615(1) Å, β = 102.67(1)º, Z = 2. The crystal structure was solved in the space group C2/m (nº 12), from X-ray single crystal data using 957 independent reflections (705 with F/σ(F) > 4, leading to R = 0.038). It consists in infinite helicoidal [FeIIFeF34]n14n? double-chains of cornersharing octahedra running along the b-axis and separated from each other by lead ions.  相似文献   

7.
Tetraammine Lithium Cations Stabilizing Phenylsubstituted Zintl-Anions: The Compound [Li(NH3)4]2[Sn2Ph4] Ruby-red, brittle single crystals of [Li(NH3)4]2[Sn2Ph4] were synthesized by the reaction of diphenyltin dichloride and metallic lithium in liquid ammonia at ?35°C. The structure was determined from X-ray singlecrystal diffractometer data: Space group, P1 , Z = 1, a = 9.462(2) Å, b = 9.727(2) Å, c = 11.232(2) Å, α = 66.22(3)°, β = 85.78(3)°, γ = 61.83(3)°, R1 (F ? 4σF) = 5.13%, wR2 (F02 ? 4σF) = 10.5%, N(F ? 4σF) = 779, N(Var.) = 163. The compound contains to Sb2Ph4 isosteric centres [Sn2Ph4]2? as anions which are connected to rods by lithium cations in distorted tetrahedral coordination by ammonia. These rods are arranged parallel to one another in the b,c-plane, but stacked along [100].  相似文献   

8.
Experiments about the Mixed Crystal Formation between Zincoxotantalates and -antimonates: ZnTa2?xSbxO6 and Zn4Ta2?xSbxO9 In the area of substituted oxotantalates of zinc two new phases of the composition A: ZnTa1·8Sb0·2O6 and B: Zn4Ta1·2Sb0·8O9 were prepared and investigated by X-ray single crystal technique. A crystallizes with tetragonal symmetry (space group D–P42/mnm, a = 4.7314; c = 9.2160 Å; Z = 2). B is monoclinic (space group C–C2/c; a = 15.103; b = 8.839; c = 10.378 Å; β = 93.81°; Z = 8). A crystallizes with trirutile structure, although there is a small replacement of Ta5+ by Sb5+. B maintains the Zn4Ta2O9 structure. One of the point positions of the M5+ ions is occupied statistically by Ta5+/Sb5+ and Zn2+. B is a metastable compound.  相似文献   

9.
On Ordered Perovskites with Cationic Vacancies. XI. Compounds of Type A B B □1/4WVIO6 ? A BIIB □W O24 with AII, BII = Ba, Sr Depending on the ionic radii of the two and three valent cations in the perovskites of type ABB □1/4WVIO6 ?; ABIIB □WO24 order disorder phenomena are present. The results of the x-ray and vibrational spectroscopic investigations as well as the diffuse reflectance spectra and the visible photoluminescence are reported.  相似文献   

10.
Ag2+ in Trigonal-Bipyramidal Surrounding New Fluorides with Divalent Silver AgM M F20 (MII = Cd, Ca, Hg; MIV = Zr, Hf) The intensively green compounds AgMMMF20 (MII = Cd, Ca, Hg; MIV = Zr, Hf) have been obtained for the first time as single crystals and investigated by X-ray methods. They crystallize in space group P63/m-C6h2 (Nr. 176) with
  • a = 1052.0(2) pm, c = 828.6(2) pm (AgCd3Zr3F20),
  • a = 1048.0(2) pm, c = 832.6(3) pm (AgCd3Hf3F20),
  • a = 1059.4(2) pm, c = 841.0(3) pm (AgCa3Zr3F20),
  • a = 1053.7(2) pm, c = 830.6(3) pm (AgCa3Hf3F20),
  • a = 1058.9(3) pm, c = 832.6(4) pm (AgHg3Zr3F20),
  • a = 1056.9(2) pm, c = 833.0(3) pm (AgHg3Hf3F20), Z = 2.
  相似文献   

11.
Jahn-Teller Effect of Mn3+ Ions in Octahedral F?-Coordination. Ligand Field Spectroscopic and Magnetic Investigations From the ligand field spectra of MnIIIF polyhedra in different host lattice structures [ABIMnF6 (elpasolite type); BIIMnF5; AIMnF4 (CsFeF4 type)] remarkable splittings of the octahedral 5Eg groundstate as the consequence of a tetragonal (or lower symmetry) Jahn-Teller component are deduced. The splittings vary between 8500 and 15500 cm?1 and can be correlated with the extent of Jahn-Teller distortion in the MnIIIF polyhedra. While the cooperative Jahn-Teller order is of ferrodistortive symmetry in the elpasolite-structure [exception: (NH4)3MnF6], the tetragonally elongated MnIIIF octahedra exhibit an antiferrodistortive order in compounds AIMnF4, as was possible to conclude from the magnetic structures found at lower temperatures. The intensities of the sharp, spin-forbidden quintet-triplet transitions in the ligand field spectra vary strongly in dependence on the temperature and the cooperative magnetic order observed for the different classes of compounds.  相似文献   

12.
On Hexagonal Perovskites with Cationic Vacancies. XIV. The Rhombohedral 12 L-Stacking Polytypes Ba2La2BII(W □O12) Rhombohedral 12 L-stacking polytypes with cationic vacancies of type Ba2La2BII-(W□O12) are reported for BII = Mg, Zn (white), Ni(light brown) and Co(brown). They crystallize in the space group R3 m, sequences (3 )(1) ? (hhcc)3. For BII = Cu, as a consequence of the Jahn Teller effect, a triclinic distorted lattice is observed.  相似文献   

13.
From the study of the hypothetical series Pb[PbInc–2pSbc]O6+p (O ? p < 1; 0 ? c < 2), the existence of the cubic pyrochlore Pb2II[In0.5Sb1.5]O6.5 has been established. This compound was obtained as an orange yellow powder, S.G. Fd4 m (No. 227), Z = 8, a = 10.5892(1) Å, V = 1187.38(3) Å3, Dc = 8.48 M gm?3. For Pb in 16(c) positions, In and Sb (1:3) randomly distributed in 16(d), oxygen atoms in 48(f) and in a half of the 8(a) sites, and oxygen positional parameter x = 0.429 (origin at center, 3 m), R = 0.062. The apparent interatomic distances (Å) are determined: Pb? O = 2.612; (In, Sb)? O = 2.019.  相似文献   

14.
Preparation of Fluorophosphates, Difluorophosphates, Fluorophosphonates, and Fluorophosphites in Fluoride-containing Urea Melts Phosphoric acid, phosphonic acid, and organylphosphonic acid react on heating in fluoride-containing urea melts in high yields to fluorophosphates, MPHO2F, organylfluorophosphonates, M1RPO2F, organylpolyfluorophosphonates, MR1CX(PO2F)2, MN(CH2PO2F)3, and phosphonoorganylfluorophosphonates, MR1CX(PO3)PO2F (M1 = K, NH4; R = organic substituent; R1 = H, organic substituent; X = OH, NH2, NR2). The reaction mechanism of the formation of fluorophosphate ions in fluoride containing urea melts is discussed.  相似文献   

15.
New Complex Fluorides with Ag2+ and Pd2+: NaMIIZr2F11 (MII = Ag, Pd) and AgPdZr2F11 For the first time single crystals of NaAgZr2F11, NaPdZr2F11 and AgPdZr2F11 have been obtained and investigated by X-ray methods. The isotypic compounds NaMIIZr2F11 (MII = Ag, Pd) crystallize triclinic, spcgr. P1 ? C (No. 2) with a = 780.9, b = 570.0, c = 583.2 pm, α = 106.1°, β = 112.2°, γ = 97.9° (NaPdZr2F11), AgPdZr2F11 is monoclinic, spcgr. C2/m? C2h (No. 12) with a = 935.1, b = 699.1, c = 780.1 pm, β = 115.7°, Z = 2 (Four circle diffractometer data, Siemens AED 2). Their structure is closeley related to the Ag3Hf2F14-type of structure.  相似文献   

16.
Addition of Transition Metal Dihalides to Acetylacetonates of Divalent Metal Ions Transition metal dihalides aMIIX2 (FeCl2, CoCl2 NiBr2 etc.) are added by the chelates MII(acac)2 under formation of binuclear complexes (THF)2MII(acac)2(aMIIX2). The octahedral and the tetrahedral centre of these compounds are connected by tridentate oxygen atoms of the two acetylacetonato ligands which are simultaneously included in four-membered rings (MIIOMII). The addition is combined with a deformation of the octahedral centre, as a prerequisite of a closest package of the atoms within the MIIOMII-ring. In the trinuclear complex (THF)2Ni(acac)2(HgCl2)2 III the interaction between the three coordination centres is weak. No structural change of the octahedral centre (THF)2Ni(acac)2 is found, but the HgCl2-groups diverge slightly from linearity (Cl? Hg? Cl 171.1°). No binuclear complexes with a central ion of the oxidation state III in the octahedral centre were obtained. One reason is the lowered donor strength of the bidentate Lewis base function of the octahedral centre [(THF)2Mn+(acac)2]n-2 with M+3 as a centralatom. Reacting systems with di- and trivalent ions prefer ionic complexes, as it is shown by the formation of [(THF)2V(acac)2][(THF)CoCl3] IV from VCl3 and Co(acac)2. The crystal structures of (THF)2Co(acac)2CoCl2 II and [(THF)2V(acac)2][(THF)CoCl3] IV were determined by x-ray diffraction. II : orthorhombic-primitive; space group P212121, Z = 4; a = 967.4(2), b = 1453.4(3), c = 1715.9(4) pm; R = 0.049 for 3084 observed reflections. IV : triclinic; space group P1, Nr. 2; Z = 2; a = 871,5(2), b = 930,6(3), c = 1865,6(6) pm; α = 101,70(2), b? = 92,45(2), γ = 91,06(2)°; R = 0,060 für 4221 observed reflections.  相似文献   

17.
Synthesis and Structure of MII[AuF4]2 (MII ? Cd, Hg) Cd[AuF4]2 and the isotypic compound Hg[AuF4]2, both are yellow, crystallize tetragonal in the space-group P4/mcc-D (No. 124) with a = 575.0/575.6 pm, c = 1034.8/1042.3 pm and Z = 2. The single-crystals were obtained by solid-state reactions in goldtubes.  相似文献   

18.
On Hexagonal Perovskites with Cationic Vacancies. XXIV. Rhombohedral 9 L Stacking Polytypes in the Systems Ba3W M □O9?x/2x?2 with MV = Nb, Ta In the system Ba3WNb□O9?x/2x/2 stacking polytypes of rhombohedral 9 L type (sequence (hhc)3; space group R3 m) can be prepared with ~1/3 ? × ? 2. For x = 2(Ba3Nb2□O8□) two modifications are formed. In the corresponding Ta system the phase with is reduced to a smaller region with x ? 1/3.  相似文献   

19.
Pb8FeIIFeF24 is triclinic: a = 20.118(3) Å, b = 5.597(1) Å, c = 9.440(2) Å, α = 89.75(2)°, β = 105.79(2)°, α = 89.38(2)°, Z = 2. The structure is solved in the unconventional space group C1 , from X-ray single crystal data using 1 641 independent reflections (R = 0.048, Rw = 0.051). It is built up from the stacking of two subnetworks along the a axis: fluorite-like [Pb8F10]n6n+ layers and infinite dimetallic [FeIIFeF14]n6n? double-chains of corner-sharing octahedra running along the b axis.  相似文献   

20.
New Ternary Silver (II) Fluorides: Ag M F14 (MIV = Zr, Hf) Single crystals of deeply blue violet coloured fluorides Ag3IIM2IVF14 (MIV = Zr, Hf) have been obtained by heating powder samples under F2/N2 (1:2) at T ≈? 600°C. The isotypic compounds crystallizes monoclinic with a = 924.9, b = 668.6, c = 907.3 pm, β = 90.30° (Ag3Hf2F14) and a = 922.5, b = 667.6, c = 906.3 pm, β = 91.30° (Ag3Zr2F14) (Four circle diffractometer data, Philips PW 1100), spcgr. C2/m-C2h3 (No. 12), Z = 2. There are two different sorts of Ag2+:Ag(1) with coordination number C.N. [Ag(1)] = 4 + 2 and Ag(2) with C.N.[Ag(2)] = 4 + 4 against F?. Ag(1) can be substituted by Cu2+, Ni2+, Zn2+, Mg2+ (all of blue/red violet colour), Ag(2) by Ca2+, Cd2+, Hg2+ (bright green). From (preliminary) powder data CuAg2Zr2F14 with a = 912.3(4), b = 661.2(2), c = 899.4(2) pm, β = 90.70° (3) is isotypic, the other compounds seems to be of closely related type of structure.  相似文献   

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