Crystal structure of K4[H2J2O10].8H20

Crystals of K₄ [H₂J₂O₁₀] 8H₂O belong to the triclinic system, space group P 1 with a = 7.161 (2) $\text{A}\text{?}\text{, b}\text{= 10,553}$ (5) $\text{A}\text{?}\text{, c}\text{= 7,081}$ (2) $\text{A}\text{?}\text{, α = 98°1′}$, β = 117°8′, γ = 90°6′ and Z = 1. The crystal structure has been determined on the basis of photographic data from 877 independent reflections, with the final R value of 6,6%. The iodine atoms are surrounded by a distorted octahedra consisting of five oxygen atoms and one OH group. The average J-O distance is 2.03 Å. There are 2 independent K atoms in the structure. K(1) has a coordination number of eight, while K(2) is surrounded by 6 (5 water molecules + one OH group) nearest neighbours.     

Crystal structures of two cesium phosphate-tellurates : Te(OH)6.Cs2HPO4 and Te(OH)6.Cs2HPO4.2CsH2PO4

Te(OH)₆.Cs₂HPO₄ and Te(OH)₆.Cs₂HPO₄.2CsH₂PO₄ are monoclinic, the first one with a = 8.204(5), b = 18.416(9), $\text{c}\text{= 6.995(5)}\text{A}\text{?}$, β = 89.89(5)°, Z = 4, space group P2₁/n, the second one with a = 9.591(6), b = 13.163(9), $\text{c}\text{= 8.367(5)}\text{A}\text{?}$, β = 106.27(5)°, Z = 2, space group P2₁/m. As already observed in previously described phosphate-tellurates the main feature of these atomic arrangements is the coexistence of two independent and different types of anions (PO₄ and TeO₆ groups) in the unit cell.     

Structures cristallines de Sc3Cu4Ge4, T.R.3Cu4Sn4 (T.R. = Y,Gd, Tb,Dy, Ho,Er), isotypes de Gd3Cu4Ge4, et de la phase apparentee Tm3Cu4Sn4

Tm₃Cu₄Sn₄ has been studied by single - crystal X - ray diffraction analysis. The structure is of a new type with space group C2/m and Z = 2:a = 16.119(2), b = 4.3935(6), $\text{c}\text{= 6.896(1)}\text{A}\text{?}$, β = 115.88(2)°, D_x = 9.32 Mgm^?3, μ(MoKα) = 52 mm^?1, F(000) = 1045, R = 0.056 for 558 independant reflexions (R_w = 0.058). Tm₃Cu₄Sn₄ is a monoclinic distorded variety of the Gd₃Cu₄Ge₄ structure type. Seven other compounds were characterized: Sc₃Cu₄Ge₄ and R. E₃Cu₄Sn₄ where R.E. = Y, Gd, Tb, Dy, Ho, Er, isostructural with Gd₃Cu₄Sn₄.     

The many phases of HUP, (UO2)[HPO4] · 4H2O. An electron-optical investigation

The prompt recrystallization of the tetragonal phyllophosphate HUP, (UO₂)[HPO₄] · 4H₂O, when rinsed with distilled water at ambient temperature, has been studied by TEM, SEM and SAD. In course of the rinsing process, to remove excess phosphorous acid, HUP underwent an orthorhombic phase change, which produced two orthorhombic phases O₁ and O₂. O₁ has $\text{a = 7.6(3)}\text{A}\text{?}$, $\text{c = 7.0(4)}\text{A}\text{?}$, and 001 absent for l odd. O₂ has $\text{a = 7.3(2)}\text{A}\text{?}$, $\text{c = 6.8(2)}\text{A}\text{?}$ and no systematic absent reflections. O₁ and O₂ are metastable and by spinodal decomposition modulate into monoclinic phases through a string of intermediate and disordered phases with the β-angle increasing from 90.0° (orthorhombic phases) to 91.3(3)°, 95(2)° and 97.7(2)° for M_2.2, M_2.1, and M_1.1 respectively, where M_1.1 is the monoclinic derivative ($\text{a = 6.9(4)}\text{A}\text{?}$, $\text{c = 6.4(4)}\text{A}\text{?}$, β = 97.7(3)°) of O₁ and M_2.1 ($\text{a = 7.3(4)}\text{A}\text{?}$, $\text{c = 12.1(3)}\text{A}\text{?}$, β = 95(2)°) together with M_2.2 ($\text{a = 14.22(4)}\text{A}\text{?}$, $\text{c = 13.08(4)}\text{A}\text{?}$, β = 91.3(3)°) are the derivatives of O₂. The crystallographic b axis could not be determined. All the abovementioned phases exhibit a striking epitaxial relationship which presumably gives the clue to the fact that these phase findings are at variance with X-ray findings given in literature. It is suggested that the phases are isomeric polymorphs of HUP.     

Etude du systeme KPO3-LaP3O9. Donnees cristal lographiques sur K2La(PO3)5 et (NH4)2La(PO3)5

The system KPO₃-LaP₃O₉ has been studied for the first time by differential thermal analysis and X ray diffraction. The system shows two compounds KLa(PO₃)₄ and K₂La(PO₃)₅ which melt in a peritectic decomposition at 880°C and 770°C respectively. An eutectic point appears at 705°C; The eutectic point corresponds to a concentration of 10% molar LaP₃O₉.Infra Red absorption spectra are typical of chain phosphates.The new compound K₂La(PO₃₅ is isotypic whith (NH₄)₂La(PO₃)₅ which has been synthetized for the first time. They belong to the triclinic system whith space group P1 and Z = 2. The parameters of the unit cell are: $\text{a = 7.309(4)}\text{A}\text{?}$$\text{b = 13.35(2)}\text{A}\text{?}$$\text{c = 7.155(7)}\text{A}\text{?}$α = 90°3(1) β = 109°17(7) γ = 89°90(4) for K₂La(PO₃)₅ and: $\text{a = 7.174(8)}\text{A}\text{?}$$\text{b = 13.38(2)}\text{A}\text{?}$$\text{c = 7.35(2)}\text{A}\text{?}$α = 90°6(2) β = 107°4(1) γ = 89°82(7) for (NH₄)₂La(PO₃)₅.     

Crystal data for two new phosphate-tellurates : Te(OH)6·2TlH2PO4·Tl2HPO4 and Te(OH)6·2TlH2PO4. Crystal structure of Te(OH)6·2TlH2PO4

We describe chemical preparations and give crystal data for two new phosphate-tellurates : Te(OH)₆·2TlH₂PO₄·Tl₂HPO₄ and Te(OH)₆·2TlH₂PO₄. Both are monoclinic with the following unit cell dimensions : a = 13.68(1), b = 6.317(5), $\text{c}\text{= 11.36(1)}\text{A}\text{?}$, β = 110.18(1)°, Z = 2, D_x = 4.82, S.G. = Cm for the first one, a = 6.285(5), b = 14.74(1), $\text{c}\text{= 7.844(5)}\text{A}\text{?}$, β = 113.38(1)°, Z = 2, D_x = 4.14, S.G. = P2₁/n for the second one. Crystal structure of the second salt shows, as in the already described phosphate-tellurates, the coexistence of independent TeO₆ octahedra and PO₄ tetrahedra in the atomic arrangement.     

La structure cristalline de Ca4Fe9O17: Des feuillets “hexagonaux” d'octaedres FeO6 et de bipyramides FeO5 lies par des tetraedres FeO4

The new calcium ferrite Ca₄Fe₉O₁₇, belonging to the CaFe_2+nO_4+n family ($\text{n}\text{=}\text{1}\text{4}$), has not the same stacking process of “FeO” blocks in “CaFeO₄” blocks, as the others terms of the series.It crystallizes in the monoclinic system, space group C2 with the parameters: $\text{a}\text{= 10,441}\text{A}\text{?}$, $\text{b}\text{= 6,025}\text{A}\text{?}$, $\text{c}\text{= 11,384}\text{a}\text{?}$ and β = 98°80. Its structure is characterized by the presence of iron atoms in oxygen octahedra and trigonal based bipyramides stacking in hexagonal layers along $\text{c}$.These layers are linked by iron atoms on tetrahedral sites. Calcium atoms are hexagonaly located around each tetrahedron.     

New tetrahedrally coordinated A2CdBr4 compounds (A = Cs,CH3NH3)

(CH₃NH₃)₂CdBr₄ and Cs₂CdBr₄ are two compounds with a tetrahedral CdBr₄-coordination. Their room temperature structures are determined. (CH₃NH₃)₂CdBr₄: monoclinic, $\text{P}\text{2}{}_1\text{c}$, $\text{a}\text{= 8.1227(13)}\text{A}\text{?}$, $\text{b}\text{= 13.4355(16)}\text{A}\text{?}$, $\text{c}\text{= 11.4194(13)}\text{A}\text{?}$, β = 96.194(11) °, z = 4. Cs₂CdBr₄: orthorhombic, Pnma, $\text{a}\text{= 10.235(5)}\text{A}\text{?}$, $\text{b}\text{= 7.946(3)}\text{A}\text{?}$, $\text{c}\text{= 13.977(5)}\text{A}\text{?}$, z = 4.     

Crystal structure of KSb2PO8

KSb₂PO₈ crystallizes in the monoclinic system, space group Co, with $\text{a}\text{= 12.306(4)}\text{A}\text{?}$, $\text{b}\text{= 7.086(2)}\text{A}\text{?}$, $\text{c}\text{= 15.037(5)}\text{A}\text{?}$, β = 95.82(3)°, Z = 8. The structure was determined from 2149 reflexions collected on a NONIUS CAD4 automatic diffractometer with MoK$\text{}\text{?}$ga radiation. The final R index and weighted R_w index are 0.019 and 0.025 respectively. The structure is built up from SbO₆ octahedra sharing corners or edges and PO₄ tetrahedra sharing corners with octahedra to form a three-dimensional network. The potassium atoms are situated in the interconnected channellike cavities.     

The sodium ytterbium orthophosphate Na3(1+x)Yb(2-x)(PO4)3

A new sodium ytterbium orthophosphate with general formula Na_3(1+x)Yb_(2-x)(PO₄)₃ (0.07 ? x ? 0.50) has been prepared and characterized. Its crystal structure has been determined from a single crystal for x = 0.50. The space group is R3?c, the lattice constants are : $\text{a}\text{= 9.12(1)}\text{A}\text{?}$, $\text{c}\text{= 21.81(6)}\text{A}\text{?}$. The structure of Na_4.50Yb_1.50(PO₄)₃ is related to that of NaZr₂(PO₄)₃. The PO₄ tetrahedra and the (Yb,Na)O₆ octahedra form a three-dimensional skeleton in which the remaining sodium atoms are inserted. This structural type is also found for the phases Na_4.50Ln_1.50(PO₄)₃ (Ln = Tm, Lu) and Na_4.50Ln_1.50(AsO₄)₃ (Ln = Er, Tm, Yb, Lu).     

The crystal structure of a new high -Nd- concentration laser material: Na3Nd(PO4)2

The crystal structure of Na₃Nd(PO₄)₂ has been determined from three-dimensional Mo-Kα diffractometer data. The space group is Pbc2₁, the lattice constants are: $\text{a}\text{= 15.874(8)}\text{A}\text{?}$$\text{b}\text{= 13.952(8)}\text{A}\text{?}$$\text{c}\text{= 18.470(9)}\text{A}\text{?}$ and there are 24 formula units per unit cell, giving a Nd concentration of 5.8 10²¹cm^?3. The final R-factor with 2329 independent reflections is 0.060. The structure of Na₃Nd(PO₄)₂, very closely related to that of Na₃La(VO₄)₂, is made up of isolated PO₄ tetrahedra and of sodium and neodymium atoms arranged in an ordered way. The tripling of the a parameter results only from the distortion of the PO₄ tetrahedra. The NdO_y polyhedra are isolated from one another and the shortest Nd-Nd distance is 4.65 Å.     

A series of rare earth silicates RE3+2M3+[SiO4]2 (OH)

A series of isotypic silicates of composition RE₂M[SiO₄]₂ (OH) with RE = La³⁺, Ce³⁺, Pr³⁺, Nd³⁺, Sm³⁺, Eu³⁺, and M = Al³⁺, Fe³⁺ has been synthesized under hydrothermal conditions. Lattice constants of two members as determined from single crystal X-ray diffraction data are: La₂Al[SiO₄]₂ (OH) (La₂Fe[SiO₄]₂ (OH)) $\text{a}{}_{\mathrm{o}}\text{= 7.401 (7.346)}\text{A}\text{?}$, $\text{b}{}_{\mathrm{o}}\text{= 5.702 (5.862)}\text{A}\text{?}$, $\text{c}{}_{\mathrm{o}}\text{= 17.072 (97.196)}\text{A}\text{?}$, gb = 112.4 (112.5°), $\text{P}\text{2}{}_1\text{c}$, Z=4.     

Crystal data on ytterbium chlorosilicate,Yb3(SiO4)2Cl

Ytterbium chlorosilicate, Yb₃(SiO₄)₂Cl, was obtained in the form of single crystals up to 1.5 × 1.5 × 0.5 mm³ as by-product of the synthesis of ytterbium oxychloride. The compound has orthorhombic symmetry (space group Pnma - D_2h¹⁶). The unit cell parameters are: $\text{a}\text{= 6.753}\text{A}\text{?}\text{, b}\text{= 17.583}\text{A}\text{?}\text{, c}\text{= 6.137}\text{A}\text{?}$. The substance is characterized by means of morphology and X-ray powder data.     

Crystal structure and magnetic properties of Cu4NiSi2S7

The structure of the compound Cu₄NiSi₂S₇ has been determined. It crystallizes in a new, monoclinic distorted sphalerite superlattice with the parameters: $\text{a}\text{= 11.551}\text{A}\text{?}$, $\text{b}\text{= 5.313}\text{A}\text{?}$, $\text{c}\text{= 8.165}\text{A}\text{?}$, β = 98.72°, $\text{V}\text{= 495.2}\text{A}\text{?}{}^3$, Z = 2, space group C2. The analogous compound Cu₄NiGe₂S₇ is isotypic. At a Neél temperature T_N = 20.2 K, Cu₄NiSi₂S₇ becomes antiferromagnetic. The magnetic moment of the paramagnetic phase is 2.6μ_B.     

Crystal structure of cubic MnSc2S4 and Mn2.29Sc1.14S4

The crystal structure of MnSc₂S₄ ($\text{a}\text{= 10.613}\text{A}\text{?}$, space group Fd3m) and Mn_2.29Sc_1.14S₄ ($\text{a}\text{= 10.523}\text{A}\text{?}$, space groupe Fd3m) were determined by three dimensional X-Ray diffraction. MnSc₂S₄ is a normal spinel structure and the atomic distribution shows that Mn_2.29Sc_1.14S₄ structure is intermediate between the rocksalt (MnS) and the spinel (MnSc₂S₄) types. Similar behaviour of Mn and Fe atoms in MnSSc₂S₃ and FeSSc₂S₃ systems was observed.     

Structure cristalline du polytype FeGa2S4α 1T

The crystal structure of the low temperature form of α-FeGa₂S₄ 1T (with $\text{a}\text{= 3,654(2)}\text{A}\text{?}$; $\text{c}\text{= 12,056(7)}\text{A}\text{?}$; Z = 1, space groupe P3̄m1) has been refined by a least squares method to a final R = 0.051 with 180 independant reflections. The sulfur stacking sequence in this polytype is…BCBC…Fe atoms occupy the octahedral voids and Ga atoms the tetrahedral voids.     

Structures cristallines des phases M2Ga2Fe2O9 (M = In,Sc) nouveaux exemples de coordinence 5 du fer

New quaternary oxides are reported : M₂Ga₂Fe₂O₉ (M = In,Sc). In₂Ga₂Fe₂O₉ has been studied by single-crystal X-ray diffraction analysis. Its structure is a new type with space group Pba2 and $\text{z}\text{=}\text{8}\text{3}\text{:}\text{a}\text{= 19.253(3)}$, b = 7.2176(2), $\text{c}\text{= 3.2581(1)}\text{A}\text{?}$, D_x = 6.05 g.cm^?3, μ(AgK_α) = 9mm^?1, F(000) = 757.1, R = 0.037 for 420 independant reflexions (R_w = 0.037). The indium are heptahedrally coordinated by seven oxygen atoms and the iron and gallium atoms by five oxygen atoms at the apices of a trigonal bipyramid.     

Hydrogen bonding in NH4HSO4. NH4H2PO4

NH₄HSO₄·NH₄H₂PO₄ is monoclinic $\text{P}\text{2}{}_1\text{n}$ with Z = 2 and the following unit cell dimensions : a = 7.723(5), b = 7.540(5), $\text{c}\text{= 7.482(5)}\text{A}\text{?}$, β = 101.32(5)°. Crystal structure of this salt has been solved with a final R value 0.028. As in the corresponding potassium salt PO₄ and SO₄ tetrahedra are randomly distributed.A complete hydrogen bonding pattern is given.     

LiPbPO4, a new lithium lead phosphate

LiPbPO₄ was prepared for the first time and single crystals of the compound were grown by the Czochralski technique. The composition crystallizes in the noncentric space group Pna2₁ (Point group mm2) with $\text{a}\text{= 7.980}\text{A}\text{?}$, $\text{b}\text{= 18.64}\text{A}\text{?}$ and $\text{c}\text{= 4.938}\text{A}\text{?}$.     

Preparation,properties and crystal structure of TlV5S8

A new sulfide of vanadium and thallium TlV₅S₈ has been prepared. It has monoclinic symmetry with space group C2 and cell dimensions: $\text{a}\text{= 17.465}\text{A}\text{?}$, $\text{b}\text{= 3.301}\text{A}\text{?}$, $\text{c}\text{= 8.519}\text{A}\text{?}$ and β = 103.94°. The structure can be described as a 3D framework made up of infinite layers and double chains which consist of VS₆ octahedra sharing faces and edges. Large rectangular tunnels host the thallium atoms. The compound shows metallic behavior.