Phase and extraction equilibria in H<Subscript>2</Subscript>O–sulfonol–HCl (H<Subscript>2</Subscript>SO<Subscript>4</Subscript>) and H<Subscript>2</Subscript>O–sodium dodecyl sulfate–HCl (H<Subscript>2</Subscript>SO<Subscript>4</Subscript>) systems

Solubility isotherms of water–sulfonol–hydrochloric (or sulfuric) acid and water–sodium dodecyl sulfate–hydrochloric acid systems at 75°C and a water–sodium dodecyl sulfate–sulfuric acid system at 50°C are constructed. Regions of two-phase liquid equilibrium suitable for use in extraction are found. Concentration parameters for extraction are determined. The interfacial distribution of a series of metal ions with and without such additional complexing reagents as diantipyrylmethane and diantipyrylheptane is studied.     

Crystal structure and quantum chemical investigation of [Cd(NTO)<Subscript>4</Subscript>Cd(H<Subscript>2</Subscript>O)<Subscript>6</Subscript>] · 4H<Subscript>2</Subscript>O

[Cd(NTO)₄Cd(H₂O)₆] •4H₂O was synthesized by mixing the aqueous solution of 3-nitro-1, 2,4-triazol-5-one (NTO) and cadmium carbonate. The single crystal structure was determined by a four-circle X-ray diffractometer. The crystal is monoclinic, space group C2/c with crystal parameters of a = 2.1229(3) nm, b = 0.6261(8) nm, = 2.1165(3) nm, β= 90.602 (3)°, V= 2.977(6) nm₃, Z = 4, D_c = 2.055 g • cm_-3, μ = 15.45 cm_-1 and F(000) = 1824. 2523 observable independent reflections with F₀4σ(F₀) were used for the determination and refinement of the crystal structure. Lorentz-polarization and absorption correction were applied. The final R is 0.0282 and wR = 0.0792. The analytical results show that the Cd⁺² has two kinds of coordinate bonds in one crystal. One Cd⁺² coordinates with 4 NTO anions and another coordinates with 6 water molecules to form a binucleate complex with a structure of tetrahedron and tetragonal bipyramid, respectively. By using SCF-PM3-MO method, the electron structure of cadmium complex of NTO has been calculated. The analysis of the calculated results shows that when [Cd(NTO)₄Cd(H₂O)₆] • 4H₂O is heated, the crystallization waters will be dissociated first and the ligand waters second and NO₂ group has priority of leaving when NTO⁻ is decomposed. Analysis of the energy level and composition of localized molecular orbitals indicates that both the two Cd²⁺ bond to the coordinating atom with 5s     

Synthesis and X-ray diffraction study of Li(H<Subscript>3</Subscript>O)[UO<Subscript>2</Subscript>(C<Subscript>2</Subscript>O<Subscript>4</Subscript>)<Subscript>2</Subscript>(H<Subscript>2</Subscript>O)] · H<Subscript>2</Subscript>O

Single crystals of Li(H₃O)[UO₂(C₂O₄)₂(H₂O)] · H₂O (I) have been synthesized and studied by X-ray diffraction. Compound I crystallizes in the monoclinic crystal system with the unit cell parameters: a = 7.1682(10) Å, b = 29.639(6) Å, c = 6.6770(12) Å, β= 112.3(7)°, space group P 2₁/c, Z = 4, R = 4.36%. Structure I contains discrete mononuclear groups [UO₂(C₂O₄)₂(H₂O)]^2? ascribed to the crystal-chemical group AB ₂ ⁰¹ M¹ (A = UO₂ ²⁺, B⁰¹ =C₂O ₄ ^2? , M¹ = H₂O), which are “cross-linked” by the lithium ions into infinite layers {Li(UO₂)(C₂O₄)₂(H₂O)₂}^? perpendicular to [010]. The hydroxonium ions are located between adjacent uranium-containing layers. A hydrogen bond system involving water molecules, oxalate ions, and hydroxonium combines the anionic layers into a three-dimensional framework.     

Physicochemical Analysis of the System Zr(SO<Subscript>4</Subscript>)<Subscript>2</Subscript>–Na<Subscript>2</Subscript>SO<Subscript>4</Subscript>–H<Subscript>2</Subscript>SO<Subscript>4</Subscript>–H<Subscript>2</Subscript>O at 25°С

The solubility in the quaternary water–salt system Zr(SO₄)₂ · 4Н₂О–Na₂SO₄–H₂SO₄–H₂O at 25°C was studied. It was found that, in the system, there is crystallization of not only Na₂SO₄ and Zr(SO₄)₄ · 4H₂O, but also sodium sulfate zirconates Na₂Zr(SO₄)₂(OH)₂ · 0.3H₂O, Na₄Zr(SO₄)₄ · 3H₂O, and Na₂Zr(SO₄)₂ · 3H₂O and two new compounds, S₁ and S₂, which are presumably Na₂ZrO(SO₄)₂ · 2H₂O and Na₂Zr₂O₂(SO₄)₃ · 6H₂O.     

Synthesis and crystal structure of complex [Mn(Imdc)<Subscript>2</Subscript>(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>] · 2H<Subscript>2</Subscript>O and its interaction with DNA

Under hydrothermal conditions, the complex [Mn(lmdc)₂(H₂O)₂] · 2H₂O (I) was synthesized and characterized by elemental analysis and IR spectrum (HImdc = 4,5-imidazofedicarboxylic acid). The crystal structure of I was determined by single-crystal X-ray diffraction (crystallizing in the monoclinic crystal system, P ₂/c space group, a = 11.000(2), b = 7.1281(14), c = 12.696(3) Å, β = 122.45(3), Z = 2. In I, the Mn²⁺ ion was chelated by two Imdc with one of their nitrogen atoms and a carboxylic oxygen atom, while two water molecules occupy the axial position of the Mn atom forming a distorted octahedral geometry. Three-dimensional structure of I was formed by intermolecular hydrogen bonds. UV-Vis and fluorescence spectra of I interacting with DNA show that insertion is the main binding mode between I and fish sperm DNA. Gel electrophoresis shows that I cleaves both supercoiled and circular pBR322 DNA to form a small molecular fragment.     

Crystal structure of Mg pivalate hydrate Mg(H<Subscript>2</Subscript>O)<Subscript>6</Subscript>(Piv)<Subscript>2</Subscript> · 3H<Subscript>2</Subscript>O

Single crystals of Mg pivalate hydrate, Mg(H₂O)₆(Piv)₂ · 3H₂O (HPiv = (CH₃)₃CCOOH) are synthesized and their structure is determined by X-ray diffraction method. The crystals are rhombic: a = 10.917(2) Å, b = 12.625(2) Å, c = 31.394(8) Å, Z = 8, space group Pbca, R ₁ = 0.0525. The Mg atom has octahedral surrounding of the O atoms of water molecules (Mg-O 2.044–2.137 Å). The cationic chains of [Mg(H₂O)₆] _∞ ²⁺ lie in the voids of doubled network anionic layers of [(H₂O)₃(Piv)₂] _∞∞ ^2? . Inside the layer, the pivalate anions alternate with water molecules in the xy plane, being bonded to them by hydrogen bonds. The cationic chains and the anionic layers are united into layered packs by hydrogen bonds between coordinated water molecules and pivalate anions and between coordinated and crystal hydrate water molecules.     

Synthesis and structural characterization of a novel tetranuclear Cu(II) complex: [Cu<Subscript>4</Subscript>L<Subscript>2</Subscript>(pic)<Subscript>4</Subscript>(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>]·2H<Subscript>2</Subscript>O

A novel Salen-type bisoxime ligand, 6,6′-dimethoxy-2,2′-[(1,4-butylene)dioxybis(nitrilomethylidyne)]diphenol (H₂L) and its tetranuclear Cu(II) complex, [Cu₄L₂(pic)₄(H₂O)₂]·2H₂O, have been synthesized and characterized by elemental analyses, IR, TG-DTA and ¹H-NMR etc. The X-ray crystal structure of the complex reveals that formation of a tetranuclear structure, which consists of four copper(II) atoms, two pentadentate L²⁻units, four picratols, two coordinated water molecules and two crystallizing water molecules. Around four copper ions are all octahedral geometries. It was demonstrated that the picratols in the tetranuclear copper(II) complex show a novel tridentate coordination mode.     

Solid-Liquid Equilibria in the Quaternary Systems KCl–MgCl<Subscript>2</Subscript>–SrCl<Subscript>2</Subscript>–H<Subscript>2</Subscript>O and NaCl–KCl–SrCl<Subscript>2</Subscript>–H<Subscript>2</Subscript>O at 348 K

Solid-liquid equilibria in the quaternary systems KCl–MgCl₂–SrCl₂–H₂O and NaCl–KCl–SrCl₂–H₂O at 348 K were measured by the isothermal solution saturation method. The composition of the equilibrium solid phase, solubilities of salts, and densities of saturated solution in the two systems were determined. Phase diagrams, water content diagrams and solution density diagrams of quaternary systems were plotted according to experimental data. The phase diagram of the quaternary system NaCl–KCl–SrCl₂–H₂O has one invariant point, three univariant curves as the boundary of NaCl, KCl and SrCl₂ · 2H₂O. This phase diagrams were simple co-saturation type without complex salt and solid solution. For the quaternary system KCl–MgCl₂–SrCl₂–H₂O, one complex salt KCl · MgCl₂ · 6H₂O (Car) had been found in this system, consisted of five univariant curves, two invariant points and four crystallization regions of MgCl₂ · 6H₂O (Bis), KCl, SrCl₂ · 2H₂O and KCl · MgCl₂ · 6H₂O. And the densities transformation rules were simply discussed. Simultaneously, the solubilities and densities data in invariant point of the quaternary system NaCl–KCl–SrCl₂–H₂O had been compared with the experimental data of previous researchers.     

Synthesis and Crystal Structure of [Co(H<Subscript>2</Subscript>O)<Subscript>6</Subscript>](C<Subscript>19</Subscript>H<Subscript>17</Subscript>O<Subscript>4</Subscript>SO<Subscript>3</Subscript>)<Subscript>2</Subscript>⋅8H<Subscript>2</Subscript>O

The title compound, cobalt 4′,7-diethoxylisoflavone-3′-sulfonate([Co(H₂O)₆](X)₂⋅8H₂O, X = C₁₉H₁₇O₄SO₃) was synthesized and its structure was determined by single-crystal X-ray diffraction analysis. It crystallizes in the triclinic space group P-1 with cell parameters a = 9.026(3) Å, b = 16.431(5) Å, c = 18.195(6) Å, α = 72.289(4)^∘, β = 87.498(4)^∘, γ = 82.775(5)^∘, V = 2550.1(13) Å⁻³, D_c = 1.419 Mg m⁻³, and Z = 2. The results show that the title compound consists of one cobalt cation, six coordinated water molecules, eight lattice water molecules, and two 4′,7-diethoxylisoflavone-3′-sulfonate anions, C₁₉H₁₇O₄SO⁻₃. Two anions have different conformations. Twelve H atoms of six coordinated water molecules, as donors, form hydrogen bonds with four oxygen atoms of sulfo-groups of two anions and eight oxygen atoms of eight lattice water molecules. In addition, π < eqid1 > ⋅ < eqid2 > π stacking interactions exist in the crystal structure, which together with hydrogen bonds lead to supramolecular formation with a three-dimensional network.     

Crystal structure and vibrational spectra of M[VO<Subscript>2</Subscript>(SeO<Subscript>4</Subscript>)(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>]·H<Subscript>2</Subscript>O (M = K,Rb, NH<Subscript>4</Subscript>)

By the hydration of MVO(SeO₄)₂ with saturated water vapors at room temperature a series of isostructural complex compounds of vanadium(V) of the composition M[VO₂(SeO₄)(H₂O)₂]·H₂O (K, Rb, NH₄) are synthesized and their physicochemical properties are studied. Based on the X-ray and neutron diffraction data, it is found that their crystal structure is composed of VO₆ octahedra linked in infinite chains by bridging SeO₄ tetrahedra. Each of the VO₆ octahedra has two short terminal V-O bonds forming a bent dioxovanadium group VO₂⁺. Two water molecules are coordinated by vanadium and one molecule is out of the first coordination sphere in the interchain space. The vibrational spectra of the studied compounds are completely consistent with their structural features.     

Crystal structure of Cs[Gd(H<Subscript>2</Subscript>O)<Subscript>4</Subscript>Re<Subscript>6</Subscript>Te<Subscript>8</Subscript>(CN)<Subscript>6</Subscript>]·4H<Subscript>2</Subscript>O

The structure of the salt Cs[Gd(H₂O)₄Re₆Te₈(CN)₆]·4H₂O (space group P-1, a = 9.436(5) Å, b = 12.365(7) Å, c = 15.187(8)Å, α = 89.104(10)°, β = 86.996(10)°, γ = 82.304(9)°) has been established by single crystal XRD. The structure of the compound features layers involving Gd³⁺ cations bound to cluster anions [Re₆Te₈(CN)₆]^4? through cyanide groups. The interlayer space contains cesium cations and crystallization water molecules.     

Crystal structure of a novel binuclear Cu(II) complex Cu<Subscript>2</Subscript>[(Dmbiim)<Subscript>4</Subscript>H<Subscript>2</Subscript>O](ClO<Subscript>4</Subscript>)<Subscript>4</Subscript>·3H<Subscript>2</Subscript>O

A novel complex, Cu₂[(Dmbiim)₄H₂O](ClO₄)₄·₃H₂O (Dmbiim = 1.1′-dimethyl-2.2′-biimida-zole), has been synthesized and studied by X-ray crystallography. Crystal data for CuO₉N₈C₁₆Cl₂H₂₂: a = 10.160(2) Å, b = 12.991(3) Å, c = 20.646(4) Å, β = 101.443(3)°, space group P2(1)/c, Z = 4, d _calc = 1.504 g/cm³, R = 0.0718. The crystal structure reveals that the complex is cage-shaped, with two Cu ions bridged by Dmbiim and each Cu ion chelated by the oxygen atom of water and four nitrogen atoms of Dmbiim.     

Synthesis and crystal structure of the complex [Nd(2-EOBA)<Subscript>3</Subscript>(phen)(H<Subscript>2</Subscript>O)]<Subscript>2</Subscript> · H<Subscript>2</Subscript>O

A novel lanthanide complex of [Nd(2-EOBA)₃(phen)(H₂O)]₂ · H₂O (2-EOBA = 2-ethoxylbenzoate, phen = 1,10-phenanthroline), has been synthesized and structurally characterized by single crystal X-ray diffraction. The complex crystallizes in monoclinic, space group P2(1)/n with a = 14.7453(18) Å, b = 12.3628(15) Å, c = 19.473(2) Å, α = 90°, β = 93.349(2)°, γ = 90°. Two Nd³⁺ ions are connected together by two bridging 2-EOBA ligands and each Nd³⁺ ion is further coordinated by two chelating 2-EOBA ligands, one chelating phen molecule and one water molecule. The coordination number of Nd³⁺ ion is nine. The coordination geometry of Nd³⁺ ion is a distorted monocapped square-antiprism.     

Synthesis and crystal structures of [K(H<Subscript>2</Subscript>O)(Piv)]<Subscript>∞</Subscript> and [K<Subscript>2</Subscript>(Phen)(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>(Piv)<Subscript>2</Subscript>]<Subscript>∞</Subscript>

A method for the synthesis of potassium pivalates (trimethylacetates) from potassium tert-butoxide and pivalic acid was proposed. The complexes of the formulas [K(H₂O)(Piv)]_∞(I) and [K₂(Phen)(H₂O)₂(Piv)₂]_∞ (II) (Piv denotes the pivalate anion and Phen denotes 1,10-phenanthroline) were obtained and characterized by elemental analysis and IR and ¹H NMR spectroscopy. The crystal structures of complexes I and II were determined using X-ray diffraction. Crystal structure I has a layered motif with two nonequivalent K atoms (C.N.s 5 + 2 and 6). The coordination of phenanthroline in II gives rise to a ribbon motif, the structure containing three nonequivalent K atoms (C.N.s 6, 6 + 1, and 8).     

Structure and thermal decomposition of Cs<Subscript>2</Subscript>HPO<Subscript>4</Subscript> · 2H<Subscript>2</Subscript>O

The thermal transformations of disubstituted cesium orthophosphate crystal hydrate under heating in air up to 400°C have been studied. The dehydration process occurs in two stages with the loss of 0.6 water molecules at 60?100°C and 1.4 water molecules at 100?160°C. Anhydrous Cs₂HPO₄ is stable up to 300°C and is completely converted into cesium pyrophosphate Cs₄P₂O₇ at 330°C. The structure of Cs₂HPO₄ · 2H₂O has been determined. The compound crystallizes in monoclinic space group P2₁/c and has the unit cell parameters a = 7.4761(5) Å, b = 14.2125(8) Å, c = 7.9603(6) Å, β = 116.914(5)°, V = 754.20(9) ų, and Z = 4 at?123°C. An earlier unknown polymorph of Cs₄P₂O₇ has been found. According to X-ray powder diffraction data, hexagonal space group Р6₃ has been proposed for the formed pyrophosphate.     

Molar heat capacity and thermodynamic properties of crystalline [Nd(Glu)(H<Subscript>2</Subscript>O)<Subscript>5</Subscript>(Im)<Subscript>3</Subscript>](ClO<Subscript>4</Subscript>)<Subscript>6</Subscript>·2H<Subscript>2</Subscript>O

A complex of neodymium perchloric acid coordinated with L-glutamic acid and imidazole, [Nd(Glu)(H₂O)₅(Im)₃](ClO₄)₆·2H₂O was synthesized and characterized by IR and elements analysis for the first time. The thermodynamic properties of the complex were studied with an automatic adiabatic calorimeter and differential scanning calorimetry (DSC). Glass transition and phase transition were discovered at 221.83 and 245.45 K, respectively. The glass transition was interpreted as a freezing-in phenomenon of the reorientational motion of ClO₄⁻ ions and the phase transition was attributed to the orientational order/disorder process of ClO₄⁻ ions. The heat capacities of the complex were measured with the automatic adiabatic calorimeter and the thermodynamic functions [H _T-H _298.15] and [S _T-S _298.15] were derived in the temperature range from 80 to 390 K with temperature interval of 5 K. Thermal decomposition behavior of the complex in nitrogen atmosphere was studied by thermogravimetric (TG) analysis and differential scanning calorimetry (DSC).     

Phase diagram of the NaCl–MgCl<Subscript>2</Subscript>–H<Subscript>2</Subscript>O system at 25–75°C and its application for MgCl<Subscript>2</Subscript> · 6H<Subscript>2</Subscript>O purification

The co-saturation line for the solid phases NaCl_(s) and MgCl₂ · 6H₂O_(s) in aqueous solution has been measured by a phase equilibrium at various temperatures. It was found that the Y _b (Y _b = w(NaCl)/(w(NaCl) + w(MgCl₂))) value of the co-saturation line increase with increasing temperature. A new recrystallization approach has been suggested for the purification of MgCl₂ · 6H₂O_(s) containing quite amount of impurity NaCl, i.e., dissolving the crude sample at low temperatures, followed by evaporating and phase separating at high temperatures. Applying the proposed approach a crude MgCl₂ · 6H₂O_(s) sample can be purified to the level of Y _b = 0.17% by only one crystallization process.     

The crystal structure of [Mg(H<Subscript>2</Subscript>O)<Subscript>6</Subscript>][VO(edta)] · 3.5H<Subscript>2</Subscript>O

The crystal structure of complex [Mg(H₂O)₆][VO(edta)] · 3.5H₂O (I) was determined by X-ray diffraction study. The crystals are monoclinic, a = 6.779 Å, b = 13.373(6) Å, c = 25.054 Å, β = 96.55°, Z = 4, space group P2₁. The unit cell contains two independent [VO(edta)]^2? anions, two independent [Mg(H₂O)₆]²⁺ cations, and seven crystal-water molecules. The coordination polyhedron of each vanadium atom is formed by five donor atoms of the edta ligand (2N + 3O) (V(1)-N(1), 2.278 Å; V(1)-N(2), 2.149 Å; V(2)-N(3), 2.301 Å; V(2)-N(4), 2.165 Å; V-O(acet), 2.00 ± 0.02 Å) and the oxygen atom of the oxo group (V-O, 1.60 ± 0.01 Å). The edta ligands and the vanadium atom form three glycinate rings: two R-type rings and one G-type ring (one acetate branch remains free), as well as an E-type ring with an asymmetric gauche configuration. The [Mg(H₂O)₆] cations are slightly distorted octahedra (Mg-O, 2.013–2.132 Å, the OMgO angles are 86.6°–94.2°). The H₂O molecules form a bifurcate system of H-bonds. The crystals of compound I belong to OD-type structures with an incomplete ordering of layers.     

Synthesis and structure of the [Co(NioxH)<Subscript>2</Subscript>(Thio)<Subscript>2</Subscript>]<Subscript>2</Subscript>SO<Subscript>4</Subscript>·2H<Subscript>2</Subscript>O complex compound

A new Co(III) complex of 1,2-cyclohexanedionedioxime and thiocarbamide with an SO ₄ ^2? anion and solvation water molecules in the outer sphere has been synthesized and its structure has been defined. Orthorhombic crystals, a = 11.659(2) Å, b = 26.448(5) Å, c = 30.142(6) Å, V = 9295(3) Å ³, Z = 8, d_calc = 1.599 g/cm³, space group Pbca; final R index is 0.0578 for 8221 reflections with I > 2σ(I). In the octahedral Co(III) complex, two 1,2-cyclohexanedionedioxime residues lie in the equatorial plane, while two thiocarbamide molecules are in the axial plane. Intramolecular bonds: N-H…O and O-H…O type hydrogen bonds and π-π interactions that stabilize the complex cations. In crystal, the components are linked by N-H…O and O-H…O hydrogen bonds into a 3D framework.