Spacer-armed binuclear copper(ii) complexes with salicylidene hydrazones of N-benzoylaminodicarboxylic acids

The structure and EPR spectra of copper(II) complexes with bis(salicylidene)hydrozones of N-benzoyl-L-aspartic and N-benzoyl-L-glutamic acids have been described. The compounds have been studied by chemical and thermal analyses, IR spectroscopy, and EPR spectroscopy. The molecular and crystal structure of the copper(II) complex with bis(salicylidene)hydrozone of N-benzoyl-L-aspartic acid (H₄L) of composition [Cu₂L · 2Py] · 2CH₃OH · H₂O has been determined by X-ray single-crystal diffraction. The crystals are monoclinic: a = 10.3316(7) Å, b = 16.7552(9) Å,c = 11.0137(6) Å, β = 105.758(3)°, space group P2₁, Z = 2. The complex has a polymeric structure composed of alternating copper-containing binuclear fragments bound to each other either via phenoxy bridges or via an aliphatic spacer (the Cu…Cu distances are 3.471 Å and 8.939 Å, respectively). The EPR spectra of the solutions of the complexes under study shows an isotropic signal comprising seven HFS lines due to two equivalent copper nuclei with the spin Hamiltonian parameters g = 2.115–2.122 and a _Cu = (36.1–36.9) × 10^?4 cm^?1, which indicates the reaization of weak exchange coupling of the paramagnetic centers.     

New gadolinium polyselenide GdSe<Subscript>1.89(6)</Subscript> in the PbFCl matlockite structure type

Optimal growth conditions for GdSe_1.85 crystals are found by the thermodynamic simulation of the Gd–Se–I system. The obtained data are used to grow GdSe_1.85 crystals by the vapor transport method using iodine as a transport agent. The grown crystals are identified by microprobe and powder XRD analyses. The structure is determined by the single crystal XRD analysis and the composition is refined. The crystal structure is in general typical of the structures of REM polychalcogenides, however, the unit cell represents the metric type unknown previously: a = 4.0562(2) Å, b = 8.1065(5) Å, c = 9.2489(5) Å, α = 115.9990(10)°, β = 90.000(2)°, γ = 89.9750(10)°, V = 273.34(3) Å3, Z = 4, d_calc = 7.659 g/cm³, space group Pb11. The experimental material for the single crystal XRD analysis is obtained on an automated Bruker X8 APEX diffractometer (MoK _α radiation, graphite monochromator, CCD detector resolution 1024×1024 pixel, distance to the detector L = 50 mm, rotation about the φ axis 15 min) by the standard procedure, 2274 measured reflections, out of them 1523 independent (R(int) = 0.0352), R factor [I > 2σ(I)] = 0.0517, R factor (all measured) = 0.0694).     

Crystal Structure of [UO<Subscript>2</Subscript>SO<Subscript>4</Subscript>{(CH<Subscript>3</Subscript>)HNCONH(CH<Subscript>3</Subscript>)}<Subscript>2</Subscript>]

The single crystals of [UO₂SO₄{(CH₃)HNCONH(CH₃)}₂] (I) were synthesized and studied by X-ray diffraction. The crystals are monoclinic, a = 6.847(1) Å, b = 14.259(3) Å, c = 14.297(3) Å, β = 93.451(4)°, space group P2₁/n, Z = 4. The main structural units of crystals I are ribbons whose composition coincides with the composition of the compound. The crystal chemical formula of the complex is AT³M ₂ ¹ (A = UO ₂ ²⁺ ).     

Structure and EPR spectra of binuclear copper(II) complexes with acyldihydrazones of benzenedicarboxylic acids and trifluoroacetylacetone

Binuclear copper(II) complexes with acyldihydrazones of benzenedicarboxylic acid and trifluoroacetylacetone have been synthesized and studied. The structure of the copper(II) complex with diacylhydrazone of 1,3-benzenedicarboxylic acid (H₄L) of composition [Cu₂L · 2LPy] has been studied by X-ray diffraction. The crystals are triclinic: a = 9.2298(4) Å, b = 11.8510(6) Å, c = 13.8314(7) Å, α = 90.780(3)°, β = 96.124(3)°, γ = 99.264(3)°, space group \(P\bar 1\), Z = 2. The number of symmetry-unrelated reflections with I > 2σ(I) 5941; R = 0.0357, R _w = 0.0589. The complex contains two equivalent copper atoms at a distance of 9.56 Å from each other in the square-planar coordination environment. The high-temperature EPR spectra of the complexes show a signal of seven HFS lines indicating the coupling of unpaired electrons to two equivalent copper nuclei (g = 2.113?2.116, a _Cu = 37.0?37.2 × 10^?4 cm^?1).     

Copper(II) trinuclear complex with trimesic acid salicylidene hydrazone: Synthesis,structure, and magnetic properties

A trinuclear copper(II) complex of trimesic acid salicylidene hydrazone (H₆L) having the composition [Cu₃L · 4Py] · CH₃OH was synthesized and characterized. By X-ray crystallography, the crystals are triclinic: a = 11.7940(4) Å, b = 13.7241(5) Å, c = 15.8993(6) Å, α = 107.4120(10)°, β = 94.2900(10)°, γ = 105.5650(10)°, space group \(P\bar 1\), Z = 2. The number of symmetrically unique reflections having I > 2σ(I) is 7636, R = 0.0465, and R _w = 0.1198. The newly prepared complex contains, in its unit cell, two [Cu₃L · 4Py] molecules which are linked to form a dimer on account of phenoxo bridges (the Cu-O bond length is 2.555 the Cu…Cu distance is 3.348 Separations between them are 9.414, 9.371, and 9.667 of temperature is satisfactorily fitted in terms of a triangular cluster model (?2J = 2.2 cm^?1) with extra intermolecular interactions (zJ′ = 0.4 cm^?1). EPR spectra of solutions at 360–380 K feature a poorly resolved HFS, whose modeling gives a satisfactory result with allowance for the interaction of unpaired electrons with three equivalent copper nuclei (g = 2.098; a _Cu = 25.8 × 10^?4 cm^?1).     

Tri-<Emphasis Type="Italic">p</Emphasis>-Tolylbismuth Diperchlorate and μ-Oxo-bis[(perchlorato)tri-<Emphasis Type="Italic">p</Emphasis>-tolylbismuth]: Synthesis and Structure

Tri-p-tolylbismuth perchlorate (1) and μ-oxo-bis[(perchlorato)tri-p-tolylbismuth] (2) have been synthesized by the reaction between tri-p-tolylbismuth dibromide and silver perchlorate and its hydrate. The complexes have been studied by chemical analysis, IR spectroscopy, and X-ray diffraction. Complex 1 is triclinic, space group Pī, Z = 4, a =10.7271(9) Å, b = 13.5585(11) Å, c = 18.1592(13) Å, α = 110.867(3)°, β = 94.944(3)°, γ = 96.888(3)°, V = 2426.3(3) Å3, ρ_calcd = 1.865 g/cm3; complex 2 crystallizes in trigonal symmetry, space group R\(\bar 3\), a = 13.1157(2) Å, c = 22.1959(2) Å, γ = 120°, V = 3306.64(8) ų, ρ_calcd = 1.777 g/cm³. The bismuth atoms in the molecular structure of complex 1 have a distorted trigonal bipyramidal coordination to the apically arranged oxygen atoms of perchlorate ions (Bi–C, 2.180(5)–2.201(5) Å; Bi–O, 2.324(4)–2.355(4) Å; OBiO axial angles, 170.1(1)°, 174.5(1)°). The structure of complex 2 contains binuclear [p-Tol₃Bi(ClO₄)]₂O molecules (Bi–O, 2.371(15), 1.9107(7) Å; OBiO axial angle, 180.0°).     

Synthesis,structure, and quantum-chemical study of tricarbonyl(4-methoxybenzaldehyde)chromium(0)

The structure of tricarbonyl(4-methoxybenzaldehyde)chromium(0) was studied by X-ray crystallography. The crystals are orthorhombic, space group P2₁2₁2₁, a = 8.040(1) Å, b = 10.510(7) Å, c = 13.279(4) Å, V = 1122.1(8) ų, Z = 4. Quantum-chemical calculations predict that this compound can exist in the gas phase as two stable conformers with almost the same energies. Their mutual transformations are examined using the density functional theory.     

Synthesis and crystal structure of <Emphasis Type="Italic">N,N</Emphasis>-dimethylbiguanidinium hexafluorosilicate

The complex [(CH₃)₂NC(NH₂)NHC(NH₂)NH₂]SiF₆ (I) was synthesized and its structure was determined by X-ray crystallography. The crystals are monoclinic: a = 7.4346(10) Å, b = 12.7628(10) Å, c = 11.0828(10) Å, β 104.080(10)°, V = 1020.01(18) ų, ρ_calc = 1.780 g/cm³, μ(MoK _α) = 0.302 mm^?1, Z = 4, space group P2₁/c. The crystals of I are composed of SiF ₆ ^2? anions (Si-F, 1.657(2)–1.699(2) Å) and N,N-dimethylbiguanidinium (H₂L²⁺) cations combined in a framework by interionic H-bonds NH···F. In the cations, protonation sites are the terminal imide groups.     

Synthesis of spiro[(6-phenyl-3,4-dihydro-2H-1,3-dioxine)-2<Emphasis Type="Italic">R</Emphasis>(<Emphasis Type="Italic">S</Emphasis>), 3′-(19′,28′-oxidooleanan)]-4-ones and X-ray diffraction analysis of their configuration

The structure of two stereoisomeric spiroadducts of allobetulone with 5-phenyl-2,3-dihydrofuran-2,3-dione was established by X-ray diffraction (XRD) analysis. The crystals of the 2R isomer are orthorhombic, P2₁2₁2₁, a = 10.825(5) Å, b = 12.849(6) Å, c = 23.358(9) Å; V = 3249(2) ų, Z = 4, d _calc = 1.200 g/cm³; the crystals of the 2S isomer hemihydrate are triclinic, P1, a = 11.505(7) Å, b = 12.192(8) Å, c = 13.123(8) Å; α = 103.35(5)°, β = 100.80(5)°, γ = 90.98(5)°; V = 1756(2) ų, Z = 2, d _calc = 1.127 g/cm³. The molecular structure of the spiroadducts is discussed.     

Synthesis and structures of polyiodide acetamide complexes of transition metals

Polyiodides of acetamide complexes of transition elements have been synthesized and studied by X-ray diffraction analysis. Compounds [M(AA)₆][I₁₀] (M = Mn, Fe, Co, Ni, Zn) are isostructural with the earlier studied cadmium compound. The crystals of [Co(AA)₄(H₂O)₂][I₁₂] are monoclinic: a = 17.486(6) Å, b = 15.015(4) Å, c = 7.8309(15) Å, β = 99.87(2)°, V = 2025.6(10) ų, space group C2/m, Z = 4. The crystals of [Ni(AA)₆][I₃]₂ are monoclinic: a = 23.032(9) Å, b = 12.176(4) Å, c = 18.274(5) Å, β = 139.22(3)°, V = 3347.0(19) ų, space group Cc, Z = 4.     

Molecular and crystal structure of a mixed-ligand cadmium complex with <Emphasis Type="Italic">p</Emphasis>-hydroxybenzoic acid and monoethanolamine

Single crystals of a mixed-ligand cadmium complex of the composition Cd(PHBA)₂(MEA) ₂ are grown from the solution of Cd(CH₃OO)₂, p-hydroxybenzoic acid (PHBA) and monoethanolamine (MEA) in aqueous ethanol. The crystallographic data are as follows: a = 11.6400(2) Å, b = 10.1363(1) Å, c = 16.6296(2) Å, β = 93.937(1)°, space group I2/a, V = 1957.44(5) ų, Z = 4. In the complex molecule located on the twofold axis, ligands of both types are bidentately bound to the cadmium ion having the coordination number 8. In the crystal structure, two H bonds of the O–H???O type combine complex molecules into layers parallel to the ab plane.     

Crystal structure and properties of AHoCuS<Subscript>3</Subscript> (A = Sr or Eu)

The structures of complex sulfides AHoCuS₃ (A = Sr or Eu) have been determined by X-ray powder diffraction. The crystals of the compounds belong to the orthorhombic crystal system; they are isostructural (space group, Pnma; structure type Eu₂CuS₃). The unit cell parameters for SrHoCuS₃ and EuHoCuS₃ are a = 10.1487(1) Å, b = 3.9332(1) Å, c = 12.9524(2) Å and a = 10.1484(2) Å, b = 3.9195(1) Å, c = 12.8499(2) Å, respectively. The temperatures and enthalpies of phase transformations of complex sulfides AHoCuS₃ (A = Sr or Eu) have been determined.     

Carbon in boron carbide: The crystal structure of B<Subscript>11.4</Subscript>C<Subscript>3.6</Subscript>

A single crystal of boron carbide obtained from a self-propagating high-temperature synthesis (SHS) product was studied by X-ray crystallography: B_11.4C_3.6, a = 5.594(2) Å, c = 11.977(7) Å, V = 324.6(7) ų, space group R3m, Z = 3, ρ_calcd = 2.56 g/cm³, R = 0.048. The content of carbon in the single crystal was estimated at ～24 at % from analysis of the unit cell parameters, bond lengths, and the volume of B_{12 ? x} C _x icosahedra, which demonstrated the possibility of obtaining by SHS carbon-rich boron carbide crystals due to the substitution of carbon atoms for boron atoms in icosahedra. Comparison of the X-ray crystallographic data for single crystals of boron carbide with the results of quantum-chemical calculations (an ab initio method (the 3–21G basis set) with geometry optimization) showed that the C-B-C group in a crystal has a nonlinear structure.     

Synthesis and crystal structure of ternary molybdate compound K<Subscript>5</Subscript>Pb<Subscript>0.5</Subscript>Hf<Subscript>1.5</Subscript>(MoO<Subscript>4</Subscript>)<Subscript>6</Subscript>

Single crystals of triple molybdate of composition 5:1:3 K₅Pb_0.5Hf_1.5(MoO₄)₆ have been grown and their crystal structure has been solved from X-ray diffraction data (an automated diffractometer X8 APEX, MoK _α -radiation, 2173 F(hkl), R = 0.0321). Trigonal unit cell parameters are: a = b = 10.739(2) Å, c = 37.933(9) Å; V = 3789(1) ų, Z = 6, ρ_calc = 4.014 g/cm³, space group \(R\bar 3\). Three-dimensional mixed framework of the structure is formed by two types of MoO₄ tetrahedra and Pb and Hf octahedra linking via common O-vertices. Potassium atoms of three types occupy large vacancies in the framework.     

Synthesis,crystal structure,and thermal behavior of dimethylgold(III) acetate

A dimethylgold(III) compound with an acetate fragment [(CH₃)₂AuOCOCH₃]₂ has been synthesized. The complex was identified from the melting point, IR, ¹H NMR, and mass spectrometry data. The temperature dependence of saturated vapor pressure over crystals has been measured and the thermodynamic parameters of sublimation have been determined by Knudsen’s effusion method with mass spectrometric measurements of the composition of the gas phase: ΔH _subl = 100.87 kJ·mol^?1, ΔS _subl = 216.67 J·mol^?1·K^?1. The thermal behavior of the solid compound was investigated by differential thermal analysis. The compound was studied by X-ray diffraction. Crystal data for C₈H₁₈Au₂O₄: a = 12.214(5) Å, b = 14.307(3) Å, c = 7.6635(15) Å; β = 103.39(3)°, Z = 4, d _calc = 2.917 g/cm³, space group P2(1)/c, R = 0.0261. The [(CH₃)₂AuOCOCH₃]₂ dimer complex with an Au...Au distance of 2.989 Å is the structural unit. The gold atom has a square plane environment of two carbon and two oxygen atoms; the Au-O distances vary from 2.118 Å to 2.139 Å. The molecules are arranged in chains linked by van der Waals interactions.     

Crystal Structures of α- and β-SrCeCuS<Subscript>3</Subscript>

The crystal structure of SrCeCuS₃, a complex sulfide synthesized for the first time, has been solved using X-ray powder diffraction data. The crystals are orthorhombic, space group Pnma. SrCeCuS₃ has two polymorphs: the high-temperature phase of Ba₂MnS₃ structural type (a = 8.1393(3) Å, b = 4.0587(2) Å, c = 15.9661(2) Å) and the low-temperature phase isostructural to BaLaCuS₃ (a = 11.1626(2) Å, b = 4.0970(2) Å, c = 11.5307(1) Å). The incongruent melting temperature and enthalpy of SrCeCuS₃ are, respectively, 1486 ± 3 K and 13.4 ± 1.5 J/g.     

Synthesis,thermal analysis,IR spectra,and crystal structure of ammonium 9-molybdomanganate

Ammonium 9-molybdomanganate (NH₄)₆[MnMo₉O₃₂]·6H₂O was synthesized and studied by single-crystal and powder X-ray diffraction, thermogravimetric analysis and IR spectroscopy. The crystals are trigonal, space group R32, a = 15.926(2) Å, c = 12.398(2) Å, V = 2723.3(7) ų, M = 1646.75, Z = 3, ρ(calcd) = 2.98 g/cm³.     

Potassium decamolybdodiferrate(III): Synthesis and characterization

Potassium decamolybdodiferrate(III) of composition K₆[Fe₂Mo₁₀O₃₄(OH)₄] · 7H₂O (compound I) is synthesized and characterized by IR spectroscopy, thermogravimetry, and powder X-ray diffraction. The crystals of compound I are monoclinic with a = 9.7482 Å, b = 6.5663 Å, c = 7.8453 Å, β = 116.81°, V = 448.15 ų, ρ = 3.115 g/cm³.     

X-ray and computational structural study of neutral <Emphasis Type="Italic">bis</Emphasis>(<Emphasis Type="Italic">N,N,N</Emphasis>′,<Emphasis Type="Italic">N</Emphasis>′-tetramethylthiophosphoramidoyl)-methylamine

The structure of bis(N,N,N′,N′-tetramethylthiophosphoramidoyl)-methylamine 1 has been determined by single-crystal X-ray diffraction. The compound 1 crystallizes in the monoclinic system, with a space group P2₁/c, a = 11.836(2) Å, b = 11.659(2) Å, c = 12.796(5) Å and β = 95.28(3)°, V = 1758.3(5) Å³ and Z = 4. The X-ray crystallographic data have been assessed by semi-empirical and ab-initio density functional theory and by Hartree–Fock molecular orbital methods. A comparative study of the results of the different methods is given.     

Crystal structure and triboluminescence of tetraethylammonium tetrakis(thenoyltrifluoroacetonato)europium

An atomic structure of complex Et₄N[Eu(ТТA)₄] (TTA is the thenoyltrifluoroacetonate anion, Et₄N⁺ is the tetraethylammonium cation) possessing strong luminescence and triboluminescence was determined by X-ray crystallography. The crystal system of centrosymmetric crystals is monoclinic: a = 10.2495(1) Å, b = 20.2162(3) Å, c = 23.5788(3) Å, β = 102.551(1)°, space group P2₁/c, Z = 4, d _calc = 1.625 g cm^–3. The crystals of the compound have an isle structure, which comprises individual complex anions [Eu(TTA)₄]^– and tetraethylammonium cations Et₄N⁺. The structural aspects of a possible model for the formation of triboluminescent properties were considered, the role of cleavage planes and disordering was discussed.