Quaternary Sulfides Research Articles

ChemInform Abstract: Synthesis and Structures of the Quaternary Sulfides K0.5Zr0.5In0.5S2 ( I) and K0.5Cr0.5Sn0.5S2 (II).

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Synthesis and structures of the quaternary sulfides K0.5Zr0.5In0.5S2 and K0.5Cr0.5Sn0.5S2

The new quaternary compounds K 0.5 Zr 0.5 In 0.5 S 2 and K 0.5 Cr 0.5 Sn 0.5 S 2 have been synthesized. K 0.5 Zr 0.5 In 0.5 S 2 has a hexagonal structure and K 0.5 Cr 0.5 Sn 0.5 S 2 has both hexagonal and trigonal phases. The two compounds have similar structures to that of CdI 2 , with double close-packed sulfur layers and transition-metal and main-group atoms disordered over the octahedral sites inside the double layers. These layers are separated by potassium ions that occupy trigonal prismatic sites

Synthesis and structure of Ba2LaAg5S6 and Ba2YAg5S6

Abstract The new quaternary sulfides Ba2LaAg5S6 and Ba2YAg5S6 have been synthesized by the reaction among BaS, La2S3 or Y2S3, Ag, and S at 1000[unk]C. The crystal structure of Ba2LaAg5S6 has been determined by X-ray diffraction techniques. Crystal data: space group C2/m, M = 1145.3, Z = 2, a = 13.909(9), b = 4.229(3), c = 11.213(7) Å, β = 94.81(3)[unk] (T = 115 K), V = 657.2 Å3, R w(F2) = 0.191 for 1611 observations and 45 variables, R(F) = 0.069 for 1594 observations having F o 2 > 2σ(F o 2). The structure has a three-dimensional framework with channels that accommodate barium ions. The lanthanum atoms have octahedral coordination and silver atoms exhibit both tetrahedral and linear coordination. From Weissenberg photography Ba2YAg5S6 has cell dimensions at room temperature of a = 14.02(2), b = 4.18(1), c = 11.28(2) Å, β = 95.0(2)[unk] and appears to be isostructural with Ba2LaAg5S6.

Synthesis and structures of the quaternary sulfides KGaSnS 4, KInGeS 4, and KGaGeS 4

The new quaternary compounds KGaSnS 4, KInGeS 4, and KGaGeS 4 have been synthesized by the reaction of K 2S 5 with elemental Ga or In, Sn or Ge, and S at 900°C. The crystal structures of the three compounds have been determined by single-crystal X-ray diffraction techniques. Crystal data: KGaSnS 4—space group P 1, Z = 4, a = 7.152(2), b = 7.847(2) , and c = 15.163(3) Å, α = 83.78(2)°, β = 87.21(2)°, γ = 63.83(2)° ( T = 153 K), R( F 2) = 0.147 for 3068 observations and 130 variables, R( F) = 0.073 for 2432 observations having F 2 o > 3 σ( F 2 o); KInGeS 4—space group P 1, Z = 4, a = 7.200(5), b = 7.739(5) , and c = 15.037(10) Å, α = 91.83(3)°, β = 99.26(4)°, γ = 112.01(4)° ( T = 294 K), R( F 2) = 0.124 for 4832 observations and 131 variables, R( F) = 0.048 for 1956 observations having F 2 o > 3 σ( F 2 o); KGaGeS 4—space group P2 1 a , Z = 4, a = 6.853(2), b = 15.956(5) , and c = 7.108(2) Å, β = 111.95(1)° ( T = 115 K), R( F 2) = 0.060 for 2235 observations and 65 variables, R( F) = 0.027 for 1925 observations having F 2 o > 3 σ( F 2 o). While the three crystal structures differ, they show close similarities. All three structures are made up of layers of metal-centered tetrahedra separated by potassium ions. The main group metal atoms are disordered to varying degrees among the tetrahedra. In each structure the tetrahedra form corner-sharing chains along the a axis and these chains are connected by pairs of edge-sharing tetrahedra. The layers in KInGeS 4 and KGaGeS 4 have the same structure while that in KGaSnS 4 is different, owing to the different ways the edge-sharing tetrahedral pairs connect the chains. All three compounds are poor conductors.

Growth and structural properties of quaternary copper thiostannates

Quaternary sulfides CuM IIISnS 4 (M III = Al, Ga, In) were characterized by SEM, DTA and X-ray investigations. CuInSnS 4 was found to crystallize stably in the cubic spinel structure with lattice constant a 0 = 10.5065(3) Å, anionic parameter u = 0.378, and cation distribution with the Cu ions in tetrahedral position and the In and Sn ions randomly distributed over octahedral sites. For CuAlSnS 4, dimorphic behaviour was observed. The low-temperature modification (α-form) exhibited a spinel-related orthorhombic cell with lattice parameters a = 7.11(1) Å, b = 7.45(1) Å and c = 10.14(3) Å. Above 700°C, the orthorhombic phase transformed into the cubic spinel structure with a 0 = 10.2225(3) Å (β-form). The structure of CuGaSnS 4 was not spinel-like. The crystal symmetry was orthorhombic with cell dimensions a = 13.954(2) Å, b = 8.886(3) Å and c = 6.476(3) Å. Single crystals of β-CuAlSnS 4 and CuInSnS 4 were grown by temperature gradient annealing of polycrystalline samples and the chemical composition checked by EDS measurements.

Lithium insertion into a new quaternary layered compound in the HgGa 2S 4 — HgIn 2S 4 s̀ystem

The electrochemical lithiation of a new layered quaternary sulphide of Hg 0.76Ga 1.27In 1.44S 5 average composition having substantial structural identity to Zn 2In 2S 5 was investigated. The discharge behaviour in lithium cells with 1M LiClO 4 solution in propylene carbonate/dimethoxyethane (1:1) was examined by means of galvanostatic measurements. The discharge curves showed a continuous voltage decrease as no plateaux were observed, and the performance was superior to that of a similar layered compound, previously analyzed, CdIn 2S 2Se 2. Due to lithium discharge, the X-ray diffraction spectrum of the cathode pellet changed, above all the relative peak intensities, and such behaviour was partly related to the typical defective structure of the sulphide having a highly disordered cation sublattice. Thermogravimetric analyses, differential scanning calorimetry, morphological and structural measurements were also carried out on the original compound in order to better characterize this new material.

Directional decomposition of some quaternary rare earth sulfides in the electron beam

Lanthanum-transition-metal-silicon sulfide samples of the general formula La 6B 2C 2S 14(where B ≡ Fe or Co; C ≡ Fe, Co or Si) have been examined by X-ray diffraction and high resolution electron microscopy (HREM). No evidence of ordering in the crystallographic B or C sites was present in the HREM images. Diffraction patterns of some crystals exhibited a light streaking mainly along [ hk0] directions. This has been attributed to a directional decomposition in the electron beam. In the initial stages, the structural decomposition was primarily in the a direction while preferred orientation was maintained in the C direction. Further irradiation of these regions resulted in the complete breakdown of the parent structure and in the subsequent crystallization of lanthanum sulfide and the corresponding transition metal sulfides.

Synthese et structure cristalline de Ba 1.14K 0.72VS 4

Single crystals of a new compound, Ba 1.14K 0.72VS 4 have been obtained from a flux of KCl at 950°C. This is the first quaternary sulfide in the BaKVS system and it is a diamagnetic insulator at room temperature. The compound has orthorhombic symmetry, Pna2 1, with unit cell dimensions a = 9.158(2)Å, b = 12.144(3)Å, c = 6.729(1)Å, Z = 4. Its structure was determined using heavy-atom methods and refined to an R value of 0.031 ( wR = 0.022); 5654 intensities were measured, using Ag Kα radiation. The structure is related to K 2SO 4-β but is not centrosymmetric and the surroundings of the potassium atoms are different. Barium and potassium atoms are coordinated, respectively, to 9 and 11 sulfur atoms, forming polyhedrons which can be described as capped trigonal prisms. The vanadium cations, V 5+, are tetrahedrally coordinated to sulfur atoms. The 0.72 potassium and 0.14 barium atoms share the same crystallographic site, explaining the relative high value of the thermal parameters.

Preparation, structure, and magnetic properties of isostructural La 3MAlS 7 and La 3MFeS 7 ( M = Mg, Mn, Fe, Co, Ni, or Zn)

A series of quaternary metal sulfides of the general formula La 3 MM′S 7 ( M = Mn, Fe, Co; M′ = Al and M = Mg, Mn, Fe, Co, Ni; M′ = Fe) consisting of linear chains of face shared MS 6 octahedra and isolated M′S 4 tetrahedra has been prepared and studied. The aluminium compounds La 3MAlS 7 ( M = Mn, Fe, Co) exhibit linear chain antiferromagnetism. Magnetic behavior of other La 3 MFeS 7 sulfides has been examined in detail. The magnetic susceptibility of La 3MgFeS 7 shows that tetrahedral site Fe 3+ undergoes a transition from S = 5 2 to S = 2 spin state around 150 K.