Syntheses, structures, and properties of Ag4(Mo2O5)(SeO4)2(SeO3) and Ag2(MoO3)3SeO3

Ag₄(Mo₂O₅)(SeO₄)₂(SeO₃) has been synthesized by reacting AgNO₃, MoO₃, and selenic acid under mild hydrothermal conditions. The structure of this compound consists of cis-MoO₂²⁺ molybdenyl units that are bridged to neighboring molybdenyl moieties by selenate anions and by a bridging oxo anion. These dimeric units are joined by selenite anions to yield zigzag one-dimensional chains that extended down the c-axis. Individual chains are polar with the C₂ distortion of the Mo(VI) octahedra aligning on one side of each chain. However, the overall structure is centrosymmetric because neighboring chains have opposite alignment of the C₂ distortion. Upon heating Ag₄(Mo₂O₅)(SeO₄)₂(SeO₃) looses SeO₂ in two distinct steps to yield Ag₂MoO₄. Crystallographic data: (193 K; MoKα, λ=0.71073 Å): orthorhombic, space group Pbcm, a=5.6557(3), b=15.8904(7), c=15.7938(7) Å, V=1419.41(12), Z=4, R(F)=2.72% for 121 parameters with 1829 reflections with I>2σ(I). Ag₂(MoO₃)₃SeO₃ was synthesized by reacting AgNO₃ with MoO₃, SeO₂, and HF under hydrothermal conditions. The structure of Ag₂(MoO₃)₃SeO₃ consists of three crystallographically unique Mo(VI) centers that are in 2+2+2 coordination environments with two long, two intermediate, and two short bonds. These MoO₆ units are connected to form a molybdenyl ribbon that extends along the c-axis. These ribbons are further connected together through tridentate selenite anions to form two-dimensional layers in the [bc] plane. Crystallographic data: (193 K; MoKα, λ=0.71073 Å): monoclinic, space group P2₁/n, a=7.7034(5), b=11.1485(8), c=12.7500(9) Å, β=105.018(1) V=1002.7(2), Z=4, R(F)=3.45% for 164 parameters with 2454 reflections with I>2σ(I). Ag₂(MoO₃)₃SeO₃ decomposes to Ag₂Mo₃O₁₀ on heating above 550 °C.     

Syntheses and structures of three new scandium selenites: Sc2(SeO3)3·H2O, Sc2 (SeO3)3·3H2O and CsSc3(SeO3)4 (HSeO3)2·2H2O

Three new hydrated scandium selenites have been hydrothermally synthesized as single crystals and structurally and physically characterized. Sc₂(SeO₃)₃·H₂O crystallizes as a new structure type containing novel ScO₇ pentagonal bipyramidal and ScO₆₊₁ capped octahedral coordination polyhedra. Sc₂(SeO₃)₃·3H₂O contains typical ScO₆ octahedra and is isostructural with its M₂(SeO₃)₃·3H₂O (M=Al, Cr, Fe, Ga) congeners. CsSc₃(SeO₃)₄(HSeO₃)₂·2H₂O contains near-regular ScO₆ octahedra and has essentially the same structure as its indium-containing analogue. All three phases contain the expected pyramidal [SeO₃]^2- selenite groups. Crystal data: Sc₂(SeO₃)₃·3H₂O, M_r=524.85, trigonal, R3c (No. 161), , , , Z=6, R(F)=0.018, wR(F²)=0.036; Sc₂(SeO₃)₃·H₂O, M_r=488.82, orthorhombic, P2₁2₁2₁ (No. 19), , , , , Z=4, R(F)=0.051, wR(F²)=0.086; CsSc₃(SeO₃)₄(HSeO₃)₂·2H₂O, M_r=1067.60, orthorhombic, Pnma (No. 62), , , , , Z=4, R(F)=0.035, wR(F²)=0.070.     

Three modifications of BaCu(SeO3)2 and the compound SrCu(SeO3)2: Preparation and crystal structure determination

The crystal structures of four hydrothermally synthesized alkaline earth-copper-selenites were determined: BaCu(SeO₃)₂-I [a = 5.247(1), B = 13.353(2), C = 8.981(1) Å, space group Pnm2₁, Z = 4, R_w = 0.024 for 1270 reflections], BaCu(SeO₃)₂-II [a = 5.256(1), B = 13.231(2), C = 8.933(1) Å, β = 90.19(1)°, space group P2₁/c, Z = 4, R_w = 0.046 for 2238 reflections], BaCu(SeO₃)₂-III [a = 8.031(1), B = 5.185(1), C = 15.823(2) Å, β = 90.83(1)°, space group C2/c, Z = 4, R_w = 0.038 for 1866 reflections], and SrCu(SeO₃)₂ [a = 7.929(1), B = 5.132(1), C = 14.997(2) Å, β = 90.53(1)°, space group C2/c, Z = 4, R_w = 0.028 for 1414 reflections; isotypic with BaCu(SeO₃)₂-III].BaCu(SeO₃)₂-I and -II contain Cu(SeO₃)₂ sheets lying parallel to (100) formed by CuO₄ “squares” and selenite groups. These sheets are topologically different: in BaCu(SeO₃)₂-I they are formed by the connection of Cu₂(SeO₃) and Cu₆(SeO₃)₄ rings while in BaCu(SeO₃)₂-II they are formed by Cu₂(SeO₃)₂ and Cu₆(SeO₃)₆ rings. The Cu(SeO₃)₂ sheets are rugged in BaCu(SeO₃)₂-I and they are slightly waved in BaCu(SeO₃)₂-II. In both compounds they are connected to each other by a fifth Cu---O bond and by the Ba atoms. In BaCu(SeO₃)₂-III and in its isotypic Sr analog the CuO₄ “squares” and the selenite groups form parallel chains [010], which are connected by the alkaline earth atoms.     

Syntheses, crystal structures, and properties of three new metal selenites Na2Co2(SeO3)3, Na2Co1.67Ni0.33(SeO3)3, and Na2Ni2(SeO3)3

Three new sodium cobalt (nickel) selenite compounds, namely, Na₂Co₂(SeO₃)₃, Na₂Co_1.67Ni_0.33(SeO₃)₃, and Na₂Ni₂(SeO₃)₃ have been hydro-/solvothermally synthesized in the mixed solvents of acetonitrile and water. Single-crystal X-ray diffraction analyses reveal that these isostructural compounds belong to the orthorhombic Cmcm space group and their structures feature three-dimensional open frameworks constructed by the two-dimensional layers of [MSeO₃] pillared by the [SeO₃]²⁻ groups. The two different types of Na⁺ ions reside in the intersecting two-dimensional channels parallel to the a- and c-axes, respectively. Their thermal properties have been investigated via TGA-DSC. The magnetic measurements indicate the existence of the antiferromagnetic interactions in these compounds.     

Extended networks, porous sheets, and chiral frameworks. Thorium materials containing mixed geometry anions: Structures and properties of Th(SeO3)(SeO4), Th(IO3)2(SeO4)(H2O)3·H2O, and Th(CrO4)(IO3)2

Three novel Th(IV) compounds containing heavy oxoanions, Th(SeO₃)(SeO₄) (1), Th(IO₃)₂(SeO₄)(H₂O)₃·H₂O (2), and Th(CrO₄)(IO₃)₂ (3), have been synthesized under mild hydrothermal conditions. Each of these three distinct structures contain trigonal pyramidal and tetrahedral oxoanions. Compound 1 adopts a three-dimensional structure formed from ThO₉ tricapped trigonal prisms, trigonal pyramidal selenite, SeO₃^2-, anions containing Se(IV), and tetrahedral selenate, SeO₄^2-, anions containing Se(VI). The structure of 2 contains two-dimensional porous sheets and occluded water molecules. The Th centers are found as isolated ThO₉ tricapped trigonal prisms and are bound by four trigonal pyramidal iodate anions, two tetrahedral selenate anions, and three coordinating water molecules. In the structure of 3, the Th(IV) cations are found as ThO₉ tricapped trigonal prisms. Each Th center is bound by six IO₃^1- anions and three CrO₄^2- anions forming a chiral three-dimensional structure. Second-harmonic generation of 532 nm light from 1064 nm radiation by a polycrystalline sample of 3 was observed. Crystallographic data (193 K, MoKα, λ=0.71073): 1; monoclinic, P2₁/c; , , , β=103.128(1), Z=4, R(F)=2.47% for 91 parameters with 1462 reflections with I>2σ(I); 2, monoclinic, P2₁/n, , , , β=100.142(2), Z=4, R(F)=4.71% for 158 parameters with 2934 reflections with I>2σ(I); 3, orthorhombic, P2₁2₁2₁, , , , Z=4, R(F)=2.04% for 129 parameters with 2035 reflections with I>2σ(I).     

Structure of two new borates YCa3(AlO)3(BO3)4 and YCa3(GaO)3(BO3)4

By replacing Mn in YCa₃(MnO)₃(BO₃)₄ with trivalent Al and Ga, two new borates with the compositions of YCa₃(MO)₃(BO₃)₄ (M=Al, Ga) were prepared by solid-state reaction. Structure refinements from X-ray powder diffraction data revealed that both of them are isostructural to gaudefroyite with a hexagonal space group P6₃/m. Cell parameters of a=10.38775(13)Å, c=5.69198(10)Å for the Al-containing compound and a=10.5167(3)Å, c=5.8146(2)Å for the Ga analog were obtained from the refinements. The structure is constituted of AlO₆ or GaO₆ octahedral chains interconnected by BO₃ groups in the ab plane to form a Kagomé-type lattice, leaving trigonal and apatite-like tunnels. It is found that most rare-earth and Cr, Mn ions can be substituted into the Y³⁺ and M³⁺ sites, respectively, and the preference of rare-earth ions to locate in the trigonal tunnel is correlated to the sizes of the M³⁺ ions.     

Investigation of the proton mobility in CsH(SO4)0.76(SeO4)0.24 crystal by H NMR spectroscopy

Crystals of CsH(SO₄)_0.76(SeO₄)_0.24 formulation were studied by ¹H NMR spectroscopy. The ¹H line-shape, the T₁ and T₂ relaxation times were determined as a function of temperature. The activation energies deduced from the temperature dependence of relaxation times were compared with the activation energy issued from conductivity measurements. The results obtained are discussed and supported by the Ngai model.     

Two new octahedral/pyramidal frameworks containing both cation channels and lone-pair channels: syntheses and structures of Ba2MnMn2(SeO3)6 and PbFe2(SeO3)4

The hydrothermal syntheses, single crystal structures, and some properties of Ba₂Mn^IIMn₂^III(SeO₃)₆ and PbFe₂(SeO₃)₄ are reported. These related phases contain three-dimensional frameworks of vertex (FeO₆) and vertex/edge linked (MnO₆) octahedra and SeO₃ pyramids. In each case, the MO₆/SeO₃ framework encloses two types of 8 ring channels, one of which encapsulates the extra-framework cations and one of which provides space for the Se^IV lone pairs. Crystal data: Ba₂Mn₃(SeO₃)₆, M_r=1201.22, monoclinic, P2₁/c (No. 14), a=5.4717 (3) Å, b=9.0636 (4) Å, c=17.6586 (9) Å, β=94.519 (1)°, V=873.03 (8) Å³, Z=2, R(F)=0.031, wR(F²)=0.070; PbFe₂(SeO₃)₄, M_r=826.73, triclinic, (No. 2), a=5.2318 (5) Å, b=6.7925 (6) Å, c=7.6445 (7) Å, α=94.300 (2)°, β=90.613 (2)°, γ=95.224 (2)°, V=269.73 (4) Å³, Z=1, R(F)=0.051, wR(F²)=0.131.     

Ba3 (VO4)2-K2 Ba(MoO4)2 and Pb3 (VO4)2-K2 Pb(MoO4)2 systems

Phase equilibria in the Ba₃(VO₄)₂-K₂Ba(MoO₄)₂ and Pb3(VO₄)₂-K₂Pb(MoO₄)₂ systems have been investigated. In the first system, a continuous series of substitutional solid solutions with the palmierite structure is formed, and in the second one, the polymorphic transition in lead orthovanadate at 100°C restricts the extent of the palmierite-type solid solution to 10–100 mol % K₂Pb(MoO₄)₂. Original Russian Text ? V.D. Zhuravlev, Yu.A. Velikodnyi, A.S. Vinogradova-Zhabrova, A.P. Tyutyunnik, V.G. Zubkov, 2008, published in Zhurnal Neorganicheskoi Khimii, 2008, Vol. 53, No. 10, pp. 1746–1748.     

Magnetic investigation of Cu(NH3)4(NO3)2

The magnetic properties of Cu(NH₃)₄(NO₃)₂ have been measured at low temperatures. Broad maxima in both the susceptibility and specific heat are observed and are consistent with linear chain behavior of a Heisenberg antiferromagnet, with J/k = 3.9 ± 0.1 K. Long-range order sets in at T_c = 0.15 ± 0.01 K, and the ratio kT_c/|J| = 0.038 is the lowest observed as yet for a one-dimensional, S = 1/2 antiferromagnet.     

Synthesis and study of (CN3H6)2[(UO2)2(C2O4)(SeO3)2] by IR spectroscopy and X-ray diffraction

Single crystals of (CN₃H₆)₂[(UO₂)₂(C₂O₄)(SeO₃)₂] were synthesized and studied by IR spectroscopy and X-ray diffraction. The compound crystallizes in the triclinic system with the unit cell parameters a = 7.1169(12) ?, b = 7.4874(10) ?, c = 8.9748(14) ?, α = 88.243(6)°, β = 74.546(6)°, γ = 81.445(6)°, space group P[`1]P\bar 1, Z = 1, R = 0.0304. The main structural units of the crystals are layers of the [(UO₂)₂(C₂O₄)(SeO₃)₂]²⁻ composition; the layers belong to the crystal chemical group A ₂ K ⁰² T ₂³ (A = UO₂²⁺ K ⁰² = C₂O₄²⁻, T ³ = SeO₃^–) of uranyl complexes. Uranium-containing complex groups are linked by electrostatic interactions and a network of hydrogen bonds with CN₃H₆⁺ guanidinium ions to form a three-dimensional framework.     

Vibrational spectra of the peroxotantalates (NH4)3[Ta(O2)4], K3[Ta(O2)4], Rb3[Ta(O2)4] and Cs3[Ta(O2)4] and the crystal structure of Rb3[Ta(O2)4]

The compounds (NH₄)₃[Ta(O₂)₄], K₃[Ta(O₂)₄], Rb₃[Ta(O₂)₄] and Cs₃[Ta(O₂)₄] have been prepared and investigated by X-ray powder methods as well as Raman- and IR-spectroscopy. In the case of Rb₃[Ta(O₂)₄] the structure has been solved from single crystal data. It is shown that all these compounds are isotypic and crystallize in the K₃[Cr(O₂)₄] type (SG , No. 121). The infrared- and Raman spectra (recorded on powdered samples) are discussed with respect to the internal vibrations of the peroxo-group and the dodecahedral [Ta(O₂)₄]³⁻ ion. Symmetry coordinates for the [Ta(O₂)₄]³⁻ ion are given from which the vibrational modes of the O-O stretching vibrations of the O₂²⁻ groups, the Ta-O stretching vibrations and the Ta-O bending vibrations are deduced.     

Synthesis and structure of a new uranyl selenate complex with 1-butylamine [CH3(CH2)3NH3](H5O2)[(UO2)2(SeO4)3(H2O)]

Crystals of a new uranyl selenate complex [CH₃(CH₂)₃NH₃](H₅O₂)[(UO₂)₂(SeO₄)₃(H₂O)] were obtained by isothermal evaporation at room temperature of its aqueous solution. The crystal structure was determined by the X-ray diffraction analysis. The observed character of the arrangement of organic molecules in the interlayer space confirms the concept of hydrophilic and hydrophobic zones.     

Structures Of Tetraammine Salts [Pt(NH3)4](N03)2, [Pd(NH3)4](N03)2, and [Pd(NH3)4]F2 H20

This contribution presents the results of a single crystal X-ray diffraction study of three ammine complexes of bivalent platinum and palladium: [Pt(NH₃)₄](N0₃)2, [Pd(NH₃)₄](N0₃)₂ and [Pd(NH₃)₄]F₂H₂O. The first two compounds are isostructural; metal atoms are located on inversion centers, all other atoms are in general positions. A three-dimensional framework is built from planar-square complex cations and nitrate ions joined by N-H...O hydrogen bonds. In [Pd(NH₃)₄]F₂H₂O, palladium atoms, as in the previous cases, are located on inversion centers, while oxygen atoms of water molecules are on the two-fold symmetry axis. A network of strong N-H...F and O-H...F hydrogen bonds linking the cations, anions, and crystallization water molecules is present in the structure.     

The thermal decomposition reactions of [Co(en)3](NO3)3 and [Co(en)3](HSO4)3

The thermal decomposition reactions were determined for [Co(en)₃](N0₃)₃ and [Co(en)₃(HSO₄)₃ in a dynamic nitrogen gas atmosphere and _vacuo, where en represents ethylenediamine. Data were obtained using thermogravimetry, DTA, thermomagnetic analysis, and mass spectrometry. The dissociation reactions in nitrogen were found to be as follows:

and

In vacuo, the dissociation process for [Co(en)₃](N0₃)₃ is the same as in nitrogen. Also, the decomposition of [Co(en)₃](HSO₄)₃ is the same except for the first step which is:

     

Crystal Structure of (H3O)4[(C2H5)4N]6 [Th2Cl4(H2O)12O]3[Re4Se4(CN)12]4

Crystals of the rhenium cluster complex (H₃O)₄[(C₂H₅)₄N]₆[Th₂Cl₄(H₂O)₁₂O]₃[Re₄Se₄(CN)₁₂]₄ are obtained in an acidic (HCl) aqueous solution by the reaction of cluster salt K₄[Re₄Se₄(CN)₁₂]·6H₂O with ThCl₄ and (C₂H₅)₄NCl. Single crystal X-ray analysis shows that the title compound is ionic and crystallizes in the cubic crystal system (a = 22.7322(3) ?, V = 11746.93(27) ?³, Z = 2, I4 3m space group, R = 0.0350). It contains [Th₂Cl₄(H₂O)₁₂O]²⁺ cations with two thorium atoms bonded to each other through the bridging oxygen atom forming an angle of 180° in the structure.     

Syntheses, crystal structures and characterizations of BaZn(SeO3)2 and BaZn(TeO3)Cl2

Two new barium zinc selenite and tellurite, namely, BaZn(SeO₃)₂ and BaZn(TeO₃)Cl₂, have been synthesized by the solid state reaction. The structure of BaZn(SeO₃)₂ features double chains of [Zn(SeO₃)₂]²⁻ anions composed of four- and eight-member rings which are alternatively along a-axis. The double chains of [Zn₂(TeO₃)₂Cl₃]³⁻ anions in BaZn(TeO₃)Cl₂ are formed by Zn₃Te₃ rings in which each tellurite group connects with three ZnO₃Cl tetrahedra. BaZn(SeO₃)₂ and BaZn(TeO₃)Cl₂ are wide bandgap semiconductors based on optical diffuse reflectance spectrum measurements.     

A novel three-dimensional malonate-bridged complex {[Cu4(4,4′- bpy)8(mal)2(H2O)4](ClO4)2(H2O)4(CH3OH)2}n

A novel malonate-bridged copper (II) compound of formula {[Cu₄(4,4′-bpy)₈(mal)₂(H₂O)₄](ClO₄)₂(H₂O)₄(CH₃OH)₂}_n (4,4′-bpy = 4,4′-bipyridine; mal = malonate dianion) has been prepared and structurally characterized by X-ray crystallography. This compound exhibits a novel three-dimensional network being composed of Cu-4,4′-bipyridine layers which are pillared by malonate bridge ligands. The copper(II) ions has two different coordination environment.