The new nickel tellurite chloride compound Ni15Te12O34Cl10--synthesis, crystal structure and magnetic properties

A new nickel tellurite oxohalide, Ni(15)Te(12)O(34)Cl(10), has been prepared by chemical vapour transport reactions and the crystal structure was determined by single-crystal X-ray diffraction. The compound crystallizes in the triclinic space group P1[combining macron] with the pseudomonoclinic cell parameters a = 10.3248(6) Å, b = 10.3249(6) Å, c = 11.6460(8) Å, α = 73.782(6)°, β = 73.782(6)°, γ = 63.51(2)°, Z = 1, R(1) = 0.0264. The Ni(2+) ions have octahedral [NiO(6)] and [NiO(4)Cl(2)] coordinations, the Te(4+) ions have one-sided [TeO(3)] and [TeO(4)] coordinations. The crystal structure can be described as consisting of nickel oxide ribbons extending along (001) that are connected by corner sharing [TeO(3)] and [TeO(4)] groups to build the open framework structure. The chlorine atoms and the Te-lone pairs are facing voids in the oxide framework. The new compound undergoes two successive antiferromagnetic ordering transitions at ∼50 K and ∼10 K. The Curie-Weiss temperature obtained from detailed evaluation of the high-temperature magnetic susceptibilities is positive indicating predominant ferromagnetic superexchange interactions between the Ni magnetic moments.

Synthesis, structural characterization, and ab initio study of Cu(5+δ)In(2+x)Sb(2-x): a new B8-related structure type

A new ternary orthorhombic compound with the formula Cu(5+δ)In(2+x)Sb(2-x), crystallizing in the space group Cmc2(1) with 36 atoms per unit cell [a = 10.1813(4) Å, b = 8.4562(4) Å, c = 7.3774(2) Å, Z = 4], has been synthesized by conventional high-temperature methods. The structure is based on the B8 archetype (NiAs/Ni(2)In) and features In/Sb ordering as well as ordering of interstitial copper. Details of the experimental study and the structural parameters of this compound are reported in the first part of the work. In the second part, ab initio calculations based on the density functional theory and the projector augmented-wave method are used to characterize the structural, thermodynamic, and phase-stability properties of the new ternary phase. The present calculations include the lattice parameters, molar volume, bulk modulus and its pressure derivative, the energy of formation from the elements, and the electronic density of states. Moreover, the present ab initio method is used to investigate the thermodynamic properties of the anti-structure Cu(5)Sb(2)In(2) compound obtained by exchanging the In and Sb Wyckoff symmetric positions.

Structural impact of platinum on the incommensurably modulated γ-brass related composite structure Pd15Zn54

The crystal structure of three incommensurately modulated γ-brass related composite structures in the Pd-Zn-Pt system has been solved from X-ray single crystal diffraction data using a 3 + 1-dimensional super space description. The compounds Pt(x)Pd(15-x)Zn(54) (x ≈ 6, 7, 10) crystallize in orthorhombic superspace group Fmmm(α00)0s0 (F = [(1/2, 1/2, 0, 0); (1/2, 0, 1/2, 0); (0, 1/2, 1/2, 0)] with the following fundamental cell dimensions: a = 4.265(1) Å, b = 9.132(1) Å, c = 12.928(2) Å, q ≈ 0.629a*; a = 4.284(1) Å, b = 9.151(2) Å, c = 12.948(4) Å, q ≈ 0.628a*; and a = 4.288(1) Å, b = 9.140(4) Å, c = 12.926(7) Å, q ≈ 0.627a*. Each structure is built by two sub-lattices-pentagonal antiprismatic columns parallel to [100] and a zigzag chain of Zn atoms running along the center of the column.

Extreme differences in oxidation states: synthesis and structural analysis of the germanide oxometallates A10[Ge9]2[WO4] as well as A(10+x)[Ge9]2[W(1–x)Nb(x)O4] with A = K and Rb containing [Ge9]4- polyanions

Semitransparent dark-red or ruby-red moisture- and air-sensitive single crystals of A(10+x)[Ge(9)](2)[W(1-x)Nb(x)O(4)] (A = K, Rb; x = 0, 0.35) were obtained by high-temperature solid-state reactions. The crystal structure of the compounds was determined by single-crystal X-ray diffraction experiments. They crystallize in a new structure type (P2(1)/c, Z = 4) with a = 13.908(1) Å, b = 15.909(1) Å, c = 17.383(1) Å, and β = 90.050(6)° for K(10.35(1))[Ge(9)](2)[W(0.65(1))Nb(0.35(1))O(4)]; a = 14.361(3) Å, b = 16.356(3) Å, c = 17.839(4) Å, and β = 90.01(3)° for Rb(10.35(1))[Ge(9)](2)[W(0.65(1))Nb(0.35(1))O(4)]; a = 13.8979(2) Å, b = 15.5390(3) Å, c = 17.4007(3) Å, and β = 90.188(1)° for K(10)[Ge(9)](2)WO(4); and a = 14.3230(7) Å, b = 15.9060(9) Å, c = 17.8634(9) Å, and β = 90.078(4)° for Rb(10)[Ge(9)](2)WO(4). The compounds contain discrete Ge(9)(4-) Wade's nido clusters and WO(4)(2-) (or NbO(4)(3-)) anions, which are packed according to a hierarchical atom-to-cluster replacement of the Al(2)Cu prototype and are separated by K and Rb cations, respectively. The alkali metal atoms occupy the corresponding tetrahedral sites of the Al(2)Cu prototype. The amount of the alkali metal atoms on these diamagnetic compounds corresponds directly to the amount of W substituted by Nb. Thus, the transition metals W and Nb appear with oxidation numbers +6 and +5, respectively, in the vicinity of a [Ge(9)](4-) polyanion. The crystals of the mixed salts were further characterized by Raman spectroscopy. The Raman data are in good agreement with the results from the X-ray structural analyses.

γ-Brass Crystallization in a Simple Monotomic Liquid

We present a molecular dynamics simulation investigating the crystallization pattern of a simple monatomic liquid model which utilize an interatomic interaction potential. The shape of the potential imitates effective interionic interaction in metallic systems. The potentials is constructed to favour icosahedral arrangement in the first coordination shell. We observe that, the system forms a thermodynamically stable solid phase exhibiting cubic symmetry. Its diffraction pattern can be identified as that of γ-brass phase, a terahedrally packed crystalline structure with 52 atoms in the unit cell. We conclude that the monatomic version of γ-brass structure generated in this simultion can be regarded as a new archetype for the γ-base structures observed in many intemetllic compounds.

Bis(isopropyl-triphenyl-phospho-nium) di-μ-iodido-bis-[iodidocopper(I)]

The title compound, (C(21)H(22)P)(2)[Cu(2)I(4)], prepared from reaction between copper powder, iodine and isopropyl triphenyl-phospho-nium iodide in hydroxy-acetone (acetol), shows an already known Cu(2)I(4) (2-) anion with a planar conformation [Cu-I range = 2.5108 (3)-2.5844 (3) Å and I-Cu-I range = 110.821 (10)-125.401 (10)°].

Bis(tetra-phenyl-phospho-nium) tetra-iodidomanganate(II) acetone monosolvate

The title compound, (C(24)H(20)P)(2)[MnI(4)]·(CH(3))(2)CO, prepared from the reaction of manganese powder, iodine and tetra-phenyl-phospho-nium iodide in acetone shows a tetra-hedral complex anion [Mn-I = 2.6868 (5)-2.7281 (4) Å and I-Mn-I = 104.011 (13)-116.164 (15)°], two tetra-phenyl-phospho-nium cations and one mol-ecule of acetone.