Eu(ClO4)3: First Single Crystals of an Anhydrous Rare‐Earth Perchlorate

Single crystals of Eu(ClO₄)₃ have been obtained by slow dehydration of a hydrous product prepared by the reaction of Eu₂O₃ with HClO₄. The crystal structure (hexagonal, P6₃/m, Z = 2, a = 924.96(9), c = 574.86(8) pm) consists of tricapped trigonal [EuO₉] prisms and [ClO₄] tetrahedra. One of the oxygen atoms in the ClO₄ group does not coordinate to Eu³⁺ and points towards the empty channel which runs in the direction [001].     

6-氯-N,N-二甲基嘧啶-4-胺的晶体结构研究

X-射线单晶衍射结果表明,所合成的6-氯-N,N-二甲基嘧啶-4-胺的晶体结构属正交晶系,Pbca空间群,晶胞参数为a=10.922(2),b=7.386(3),c=17.861(6)。由于在其晶格内存在着潜在的C—H…N和C—H…Cl两类分子间弱相互作用力,形成了二维网络结构,化合物变得更加稳定。     

Preparation and Crystal Structure of Li4[TaN3]

The new lithium nitridotantalate(V), Li₄[TaN₃], was prepared by reaction of Li₁₅[CrN₄]₂N with the wall of a welded Ta ampoule in the presence of metallic Li at 1470 K. Li₄[TaN₃] forms colourless single crystals (platelets, space group Ibca, No. 73, a = 491.85(4) pm, b = 973.59(6) pm, c = 1415.0(1) pm, Z = 8, R1 = 0.0288). The crystal structure is described as Li₂O superstructure with ordered occupation of the tetrahedral sites by Li and Ta. The resulting arrangement leads to infinite chains [TaN₂N_2/2^4—] running along [100].     

Synthesis and Modulated Crystal Structure of KBaNbS4

Single crystals of KBaNbS₄ have been prepared by the reaction of Nb with an in situ formed melt of K₂S₃, BaS, and S at 500 °C. Satellite reflections observed in X‐ray diffraction experiments of these crystals indicate the presence of a one‐dimensional lattice distortion. The modulated structure has been solved and refined from X‐ray data using the superspace group approach. KBaNbS₄ can be described in the (3 + 1)‐dimensional superspace group Pnma(α00)0s0 with lattice parameters a = 9.187(1), b = 7.001(1), and c = 12.494(1) Å and a modulation vector q = (0, 0.629(1), 0). In the structure the NbS₄ tetrahedra are stacked along the a axis and show a slight tilting against each other. The K⁺ and Ba²⁺ ions follow this tilting, both are slightly shifted from their positions in the average structure. The modulation does not lead to a significant change in the coordination spheres of the metal atoms. The small effects of the modulation correspond to the relatively weak intensities of the satellite reflections. Results of temperature dependent X‐ray investigations indicate that K⁺ librates at higher temperatures and the surrounding S^2? anions follow this motion. With decreasing temperature the libration of K⁺ is reduced and the coordination geometry freezes under formation of an incommensurate modulation. The heavier Ba and Nb atoms are also affected by positional modulation of the substructure and accommodate to their environment.     

Crystal Structure of [Et_4N][Sm(S_2CNEt_2)_4]

The crystal structure of .[Et4N][Sm(S2CNEt2)4] was determined by X-ray diffraction technique. The crystal crystallizes in monoclinic system, space group P21/n with a= 1. 1695(3), b=2.0821(6), c=1.7420(7) nm, β=99. 79(3)°? Z=4, Dc= 1. 39 g/ cm3, μ(Mo/KTσ) = 18. 4 cm-1, F(000) = 1812. The structure was solved by Patterson and Fourier techniques and refined by least-squares method to a final conventional R of 0. 053 for 3116 (Ⅰ> 3σ- (Ⅰ)) reflections. Each asymmetric unit contains two ions [Sm (S2CNEt2)4]-1 and [Et4N] +1, having distance between central atoms N5 and Sm3+ to be 0. 6522 nm. The atom Sm is coordinated by eight sulphur atoms. The Sm-S distance lies in the range of 0. 285-0. 290 nm with an average of 0. 288 nm.     

Eu4Bi3: Crystal Structure,Magnetic and Electronic Properties

The Eu? Bi system contains the phases Eu₅Bi₃, Eu₄Bi₃ and Eu₁₁Bi₁₀. The structure types of these phases have been determined by powder X-ray diffraction. Crystals of Eu₄Bi₃ (cubic, space group I4 3d; a = 9.920 Å, Z = 4, T = 130 K, R1/wR2 = 4.86/10.84%) were obtained in low yield by reaction of Eu, Mn, and Bi in the ratio 14:1:11 in a closed niobium tube (heating rate 30°C/h; reaction at 1050°C for 300 h, cooling rate 100°C/h). The crystal structure consists of distorted octahedra made up of six Bi coordinated to a central Eu atom. Eu is also coordinated to a three other Eu atoms and forms a three-dimensional network composed of interconnected rings. The Bi atoms are coordinated to eight Eu atoms. High yields of Eu₄Bi₃ can be prepared by reacting stoichiometric amount of the elements in a sealed tantalum tube at 1100°C for 24 h. Temperature dependent magnetic susceptibility is consistent with antiferromagnetic behavior with an ordering temperature of 18 K. The data could be fit with the Curie-Weiss law and a moment of 7.38 μ_B/Eu is obtained, consistent with all Eu atoms being Eu¹¹. Temperature dependent resistivity indicates that Eu₄Bi₃ is a metal with a room temperature resistance of 1.3 Ωcm.     

Competitive Coordination of the Uranyl Ion by Perchlorate and Water ‐ The Crystal Structures of UO2(ClO4)2·3H2O and UO2(ClO4)2·5H2O and a Redetermination of UO2(ClO4)2·7H2O

By slow evaporation of solutions containing UO₂(ClO₄)₂ and an excess of HClO₄, single crystals of [UO₂(ClO₄)₂(H₂O)₃] ( 1 ) and [UO₂(H₂O)₅](ClO₄)₂ ( 2 ) were obtained and their structures were determined. From similar solutions prepared from stoichiometric amounts of UO₃ and perchloric acid, crystals of [UO₂(H₂O)₅](ClO₄)₂·2H₂O ( 3 ) were obtained. The trihydrate (monoclinic, P2₁/c, a = 545.44(1) pm, b = 1811.09(5) pm, c = 1032.46(2) pm, β = 90.016(1)°) consists of uranyl ions, which are coordinated by two monodentate perchlorate ions and three water molecules. The pentahydrate (monoclinic, P2₁/n, a = 529.35(2) pm, b = 1645.43(6) pm, c = 1480.18(6) pm, β = 99.847(1)°) contains uranyl ions coordinated by five water molecules. The same structural unit can be found in the heptahydrate, whose structure was re‐determined (orthorhombic, Pbcn, a = 920.9(3) pm, b = 1067.9(3) pm, c = 1445.7(3) pm). In this structure, two molecules of water of crystallization are present.     

Synthesis and Crystal Structure of the Cesium Silver ­Permanganate Cs3Ag[MnO4]4

After successful syntheses and structural refinements of the already known permanganates of cesium (Cs[MnO₄]) and silver (Ag[MnO₄]) we started to blend aqueous solutions of both components in various molar ratios. From crystallization experiments of these mixtures only three species of crystals with different chemical compositions were obtained: tricesium monosilver tetrakispermanganate (Cs₃Ag[MnO₄]₄) and, depending upon the respective ratio, either additional silver permanganate or surplus cesium permanganate, namely. The new title compound crystallizes in the orthorhombic space group Pnnm (no. 58) with two formula units per unit cell and cell dimensions of a = 764.53(4), b = 1883.57(9) and c = 584.34(3) pm. The crystal structure of Cs₃Ag[MnO₄]₄ consists of two crystallographically distinguishable cesium cations. (Cs1)⁺ is surrounded by fourteen oxygen atoms constructing a slightly distorted bicapped hexagonal prism. These polyhedra are connected through edge‐sharing with two other polyhedra of this kind to form chains along [001]. The chains are linked to each other via sixfold coordinated Ag⁺ cations (d(Ag–O) = 238–246 pm), arranged in such a manner that they link three oxygen atoms of two cesium polyhedra, leading to a two‐dimensional layer spreading out parallel to the (001) plane. Together with the two crystallographically different tetrahedral oxomanganate(VII) anions [MnO₄]^– (d(Mn–O) = 161–162 pm) the other kind of cesium cations ((Cs2)⁺ with CN = 13) finally connect these layers three‐dimensionally.     

Y[PS4]: An Unusual ABX4 Compound with a PtS-Related Crystal Structure

Pale yellow single crystals of Y[PS₄] (tetragonal, I4₁/acd; a = 1065.72(5), c = 1899.23(9) pm, Z = 16) can easily be obtained by the reaction of the elements without using a flux to avoid the entrapment of alkali metals. The structure consists of isolated [PS₄]^3- tetrahedra (d(P-S) = 203 pm, 4×) each surrounded by four Y³⁺ cations resulting in a S₄N₄-analogous arrangement of the metal cations and sulfur atoms about the phosphorus in the center of this polyhedron. Both crystallographically different Y³⁺ cations are eightfold coordinated by sulfur in the shape of trigonal dodecahedra (d(Y-S) = 280 - 300 pm, CN = 8) which in turn belong to four exclusively edge-attached [PS₄]^3- tetrahedra. These build up a distorted cubic closest packing where the Y³⁺ cations are situated in one half of the tetrahedral holes the same way as S^2- in the Pt²⁺ arrangement of the PtS-type structure.     

Synthesis,Crystal Structure,and Properties of Ag3SbO4

From solid state reactions of Ag₂O and Sb₂O₃ at high temperatures under elevated oxygen pressures a new silver antimonate, Ag₃SbO₄, has been obtained. The crystal structure of Ag₃SbO₄ was determined from powder data (P4₁22 (no. 91) with a = 7.0436(1), c = 8.8665(1) Å, V = 439.88(2) Å³, Z = 4, R_p = 8,75 %, R_wp = 11.92 %, R_exp = 13.60 % ). Ag₃SbO₄ is isostructural to Ag₃RuO₄. The crystal structure is an ordered variant of the NaCl structure and consists of silver atoms and helical chains of edge sharing SbO₆ octahedra running along c. Ag₃SbO₄ is diamagnetic and semiconducting (ρ = 50 Ω · cm at ambient temperature, E_a = 0.098 eV), and starts to decompose at 620 °C.     

Synthesis and Crystal Structure of LiZn13

By simultaneous deposition of zinc and lithium onto a cooled sapphire substrate, LiZn₁₃ was obtained for the first time. It crystallizes in the NaZn₁₃ structure type (Fmc, a = 1234.92(6) pm, R_p = 5.4 %, R_wp = 6.9 %, structure analysis with the Rietveld‐method). Single‐phase LiZn₁₃ forms from a hexagonal Li_0.07Zn_0.93 alloy, deposited at –196 °C, during heating up to room temperature. Above room temperature LiZn₁₃ decomposes.     

Crystal Structure Analysis by Neutron Diffraction II

This second part of the article “Crystal Structure Analysis by Neutron Diffraction” deals with the diffraction of neutrons by magnetically ordered crystals. Neutron diffraction is at present the only reliable method for the determination of the magnitude, direction, and spatial distribution of magnetic moments in crystalline substances. Since the magnetic moments are essentially due to the unpaired electrons, the distribution of these electrons in the crystal can be measured in this way.     

Crystal Structure of Rubidium Tetraiodothallate(III) Dihydrate,RbTlI4·2H2O

The crystal structure of RbTlI₄·2H₂O (cubic, , Nr. 226, Z = 24, a = 1993.5(2) pm, 327 unique reflections with I_o > 2σ(I_o), R₁ = 0.0305, wR₂ = 0.0702, GooF = 1.1199, T = 298(2) K) is characterized by an ReO₃ analogous arrangement of rubidium centered [TlI₄] tetrahedra. The cuboctahedral cavities of this structure are filled with crystal water molecules and additional disordered rubidium cations.     

Synthesis and Crystal Structure of a new O,N Lithium Coordination Polymer

The reaction of 4‐Amino‐6‐methyl‐1, 2, 4‐triazine‐3(2H)‐thione‐5‐one (HAMTTO) with n‐butyl lithium in dimethoxyethane (DME) gives the complex [Li(DME)(AMTTO)] ( 1 ). 1 was characterized by elemental analysis, IR‐ and mass‐spectrometry and an X‐ray structure analysis [space group P2₁/n, Z = 4, lattice dimensions at —80 °C: a = 867.6(1), b = 1721.5(2), c = 931.8(1) pm, β = 112.81(1)°, R₁ = 0.0315. The complex is a coordination polymer along [001] with a zig‐zag arrangement.     

Synthesis,Structure, and Properties of LiNb6Cl15

Black single crystals of LiNb₆Cl₁₅ were obtained from reactions of Nb powder, NbCl₅ and LiCl in sealed niobium tubes at 850°C. The heavy atom structure of LiNb₆Cl₁₅ (Ia3 d (no. 230), Z = 16, a = 2055.5(2) pm at 100 K, R(F) = 0.028, R(F²) = 0.053) is isotypic with the structure of Ta₆Cl₁₅. The [Nb₆Cl₁₂]²⁺ clusters in the structure are three-dimensionally interconnected via three additional Cl^a?a. These bridge all vertices of niobium clusters, consistent with [Nb₆Cl₁₂ⁱCl]^? (the Nb? Cl^a–a? Nb angles are 140°). At low temperatures the lithium ions are disordered over one-third of sites (48 f), occupying cavities inside of two distorted corner-sharing tetrahedra of chloride. These positions for lithium represent the narrowest sections of infinite channels in the structure built up by chloride. An increased lithium ion mobility is obtained above 170 K by ⁷Li-NMR measurements.     

The Crystal and Molecular Structure of Acetatochlorobis(4-methylpyridine) oxovanadium (IV)

The crystal and molecular structure of the title compound, VOCl(O₂CCH₃)(4-CH₃C₅H₄N)₂, has been determined by single-crystal X-ray diffraction. The material crystallizes in the space group P1(#2) with a = 7.822(2), b = 8.023(1), c = 14.841(2) Å, α = 99.73(1)°, β = 91.41(1)°, and γ = 117.13(1)°. The coordination geometry around the vanadium is a highly distorted octahedron. The molecule is remarkable for being a monomeric oxovanadium(IV) carboxylate. A generalized synthetic strategy is proposed for the preparation of oxovanadium(IV) monomers.