Structure of 4,4′-butane-(1,4,7-three-p-tolylsulphonyl-1,4,7-three amine) diphthalonitrile

Abstract

The crystal structure of the title compound, C₄₁ H₃₅ N₇ O₆ S₃ was determined as monoclinic by single crystal X-Ray diffraction technique. The molecular structure was identified by IR, ¹H-NMR, ¹³C-NMR and elemental analysis. The crystal parameters of this compound are as follows: monoclinic P 2 1/n, a = 12.694(2) Å, b = 26.204(2) Å, c = 13.005(2) Å, β = 102.95(2)°, V = 4216.02(1) Å.³, Z = 4, Dx = 1.289 g/cm³, F(000) = 1704, λ (MoKα) = 0.71070 Å, μ = 0.2 mm^?1. The structure was solved by SHELXS-97 and refined by SHELXL-97. R = 0.06 for 3178 observed reflections with I > 2σ (I).     

Structure of Quinoline-4-Carboxaldehyde-2,4-Dinitrophenyl-N Methylhydrazone

Abstract

The crystal structure of the title compound, C₁₇H₁₃N₅O₄, has been determined by single crystal x-ray diffraction at room temperature. The molecule is not planar, with dihedral angles of 7.2(1)° between the quinoline ring and N-methylhydrazone group, and 17.45(2)° between the N-methylhydrazone group and the phenyl ring. The crystal parameters of this compound are as follows: monoclinic P 21/n, a=9.525(2)Å, b = 15.192(2) Å, c = 11.302(2) A, β = 94.722(3)°, V = 1629.8(6) ų, Z = 4, Dx = 1.432 g/cm³, F(000) = 728, λ (MoKα) = 0.71070 Å, μ = 0.106 mm^?1, R_int = 0.017. The structure was solved by SHELXS-86 and refined by SHELXL-93. R = 0.07 for 2438 observed reflections with I > 2σ (I).     

Structure of bis(4-Methyl Pyridine) Cadmium Tetracyanonickelate

Abstract

The structure, C₁₆H₁₄CdN₆Ni, consist of corrugated polymeric networks made up of tetracyanonickelate ions coordinated to Cd. The 4-methyl pyridine molecules bound to Cd in trans positions are located on both sides of the network. The bonding in the networks occurs because of a departure of the Ni-C-N-Cd sequence of atoms from linearity at the C and N positions. The crystal structure of the title compound was determined as monoclinic by single crystal X-Ray diffraction technique. The crystal parameters of this compound are as follows: monoclinic C2/m, a=18.156(2) Å, b=7.581(2) Å. c= 6.983(2) Å, β = 110.09(2)°, V = 902.6(5) ų Z=2, Dx = 1.698 g/cm³, F(000) - 456, λ (MoKα) = 0.71070 Å, μ = 2.121 mm^?1. The structure was solved by SHELXS-86 and refined by SHELXL-93. R = 0.02 for 1074 observed reflections with I > 2[sgrave] (I).     

Structure of 5-Allyl-2-hydroxy-3-methoxyazobenzene

Abstract

5-allyl-2-hydroxy-3-methoxyazobenzene was preperad by the reaction of 4-allyl-2-methoxyfenol and benzenediazoniumchloride and crystallized from dimethylsulphoxide to yield crystals suitable for analysis. The molecular structure was identified by UV-VIS, IR, ¹H-NMR, ¹³C-NMR and elemental analysis. The crystal structure of the title compound was determined as monoclinic by by single crystal X-Ray diffraction technique. The crystal parameters of this compound are as follows: monoclinic P 2 1/n, a=5.559(2) Å,b=14.900(2) Å, c= 17.573(29 Å, P = 98.58(1)?, V = 1439.3(2) ų, Z = 2, Dx = 0.610 g/cm³, F(OOO) = 284, λ (MoKα) = 0.71070 Å, μ = 0.041 mm^?1. The structure was solved by SHELXS-86 and refined by SHELXL-93. R = 0.09 for 1107 observed reflections with I > 2σ (I).     

Crystallographic and vibrational study of hexanitroethane

The crystal structure of hexanitroethane has been determined in the low-temperature ordered phase at 145 K (P2₁/c: a = 10.152(2) Å, b = 9.311(2) Å, c = 10.251(2) Å, β = 97.54(1)°, V = 960.6(3) ų, Z = 4 with 2 non-equivalent molecules in the unit cell).The far-infrared, infrared and Raman spectra of hexanitroethane in both low-temperature ordered and high-temperature disordered crystal phases were recorded. The internal modes are interpreted with the help of normal coordinate analysis and a conformational analysis with the MNDO method. The transition mechanism is discussed.     

Trissarcosine barium(2 + ) dibromide—a new complex of N‐methylglycine

We obtained a new complex containing sarcosine (CH₃NH₂⁺CH₂COO⁻) and barium(2 + ) dibromide (TSBB) in 3:1 molar ratio, as well as its deuterated analog. Single‐crystal X‐ray diffraction measurements show that TSBB crystallizes in the monoclinic system, space group P2(1)/c. The unit cell parameters are as follows: a = 18.345(4) Å, b = 10.668(2) Å, c = 8.9212(18) Å, β = 91.86(3)°, and Z = 4. The structure was determined with final R₁ = 0.0396 (for I > 2σI). The crystal possesses a pseudohexagonal symmetry down c axis showing the resemblance to the crystal structure of trissarcosine calcium chloride (TSCC). There are N HBr hydrogen bonds (HB) of six types. TSBB crystal undergoes a phase transition at 416 K (heating)–415 K (cooling) of continuous nature. The spectroscopic [Infrared (IR) and Raman] investigation of the crystal was performed at room temperature. The results are discussed with respect to the crystallographic data, as well as the results obtained for TSCC crystal. Copyright © 2008 John Wiley & Sons, Ltd.     

Crystal Structures of Tetrakis‐(4‐chlorophenylthio)‐butatriene and Tetrakis‐(tert‐butylthio)‐butatriene

Tetrakis‐(4‐chlorophenylthio)‐butatriene (3a) and tetrakis‐(tert‐butylthio)‐butatriene (3b) were synthesized, and their crystal structures were determined. The compound 3a is monoclinic, space group P2₁/c, a=6.9785(8), b=8.6803(9), c=22.884(2) Å, β=93.887(6)^o, V=1383.0(3) ų, Z=2. The compound 3b is monoclinic, space group P2₁/n, a=11.0615(6), b=10.8507(4), c=11.2717(6) Å, β =116.427(2)^o, V=1211.5(1) ų, Z=4. The title compounds 3a and 3b reside on an inversion center so that only half of the molecule is crystallographically unique. Both compounds are not planar. The crystal structures of 3a and 3b have cumulated double bonds. The C7–C8–C8ⁱ and C5–C6–C6ⁱ angles that show the linearity in both structures, respectively, are 176.4(3)° in 3a and 175.6(2)° in 3b.     

Mössbauer spectra and molecular structure of spin-crossover iron (III) complexes of monoclinic form with hexadentate ligands derived form triethylenetetramine and salicylaldehyde [Fe(sal2trien)]BPh4·acetone

Iron (III) complexes of [FeL]BPh₄·acetone containing the hexadentate ligand derived from triethylenetetramine and salicylaldehyde have been synthesized. These complexes were grown in two crystalline forms; monoclinic and twin crystals. The spin-state interconversion rate of the monoclinic form is as fast as the inverse of the Mössbauer lifetime (1×10^?7 s) above 200 K. The crystal structure of the monoclinic form (complex a) was determined at 290 K and to be of space group P2₁/a, with a=27.418 (4), b=10.097 (2), c=14.726 (3) Å, β=98.00 (1)°, and Z=4. The average bond distances of Fe?O (1.875 Å), Fe?N_imine (1.988 Å) and Fe?N_amine (2.069 Å) are in good agreement with the expected values for the transition spin-state between high- and low-spin states. Twin crystals are in a high-spin state over the temperature range 78–320 K.     

15N Isotopic Effects on the Raman Spectra of Tribromoacetamide

Abstract

¹⁵N-Tribromoacetamide has been synthesized with an isotopic content of 99, 4%, its Raman spectra have been recorded in the range 4.000–50 cm^?1. The isotopic shifts arising from ¹⁵N have been determined and interpreted. We have assigned the vibrational spectra of Br₃CCONH₂ and some overtones, combinations and difference bands. The molecular structure of tribromoacetamide has been studied employing the Ab Initio teoretical calculations and the Teller - Redlich isotopic product rule has been applied by assuming these geometrical parameters:

rCN = 1.4623 Å, rCC = 1.6014 Å, rBrC = 1.9468 Å, rCO = 1.2144 Å, rNH = 1.0292 Å, C-C-Br = 108.83320, C-C-0:118.2440, C-C-N:120.4137, C-N-H:110.45930     

High-pressure X-ray diffraction study of dimedone

Abstract

Dimedone (i.e. 5.5-dimethyl-I,3-cyclohexanedione) crystals, C₈HI₁₂O₂, have been studied at high pressures by X-ray diffraction using a Merrill-Bassett diamond-anvil cell. The unit-cell dimensions have been measured to 1.20(5) GPa and the structure has been determined at 0.95(5) GPa. The crystal compressibility is strongly anisotropic and non-linear, relatively strong compressibility of the crystals is observed along the helices of the hydrogen-bonded molecules. Small anomalous changes of the unit-cell dimensions are observed between 0.1 and 50 MPa. The main structural changes are compression of intermolecular contacts, but also an alongation of the O=C bond—accompanied with the compression of the hydrogen bond involving the carbonyl oxygen atom—has been observed. This elongation is consistent with similar effects reported on compression of the hydrogen bonds in 1,3-cyclohexanedione and 2-methyl-1,3-cyclopentanedione. Crystal data for the dimedone structure at 0.95 GPa: monoclinic, P2₁/c, a=9.909(6), b= 6.505(3), c=12.313(6) Å, β=14.51°, V=722.1(5) Å, Z=4, R=0.139 for 336 independent reflections.     

Precious Metals - Part 2 - The Spectroscopic Characterisation and X-Ray Crystal Structure of Pd2(Pph3)3Cl5O

This work is on the synthesis and characterisation of a new phosphine stabilised palladium compound. the compound was first obtained from the rejects of cluster syntheses stored in the laboratory. Later on, it was prepared from PdCl₂ and triphenyl phosphine. the compound was characterised by ³¹P {¹H} NMR, UV/visible spectroscopy and elemental analysis. the crystal and molecular structure of Pd₂(PPh₃)₃Cl₅O was determined by X-ray analysis. the compound crystallizes in orthorhombic space group Pbca, N° 61, a = 19.009(2)Å, b=22.283(2)Å, c=23.726(2)Å, V=10050(20)ų, Z=8 residuals R[I>2σ(I)]=0.0457 and R(all) = 0.0636, MoKα radiation, 20 °C.     

Phase transitions in rubidium hydrogen sulfate: crystal structures at 293 and 200 K

The crystal structure of the paraelectric phase of rubidium hydrogen sulfate has been redetermined at room temperature to be monoclinic with a = 14.3503(14), b = 4.6187(4), c = 14.3933(14)?Å, β = 118.03(1)° (space group P2₁/n). Both the sulfate groups are found to be ordered, unlike in previous reports. The crystal structure of the ferroelectric phase at 200?K belongs to the noncentrosymmetric space group Pn with a = 14.2667(12), b = 4.5878(4), c = 14.2924(12)?Å, β = 118.01(1)°, with distorted sulfate groups. The change in the Rb coordination is discussed in terms of bond-valence-sum calculations. Variable-temperature powder X-ray diffraction patterns at temperatures above 393?K indicate a possible reduction in symmetry, suggesting a phase transition.     

Synthesis of the new oxocuprate Cu5Bi2B4O14 and investigation of its structural, magnetic, and resonant properties

Single crystals of the new compound Cu₅Bi₂B₄O₁₄ are grown and its structural, magnetic, and resonant properties are investigated for the first time. It is found that the Cu₅Bi₂B₄O₁₄ crystal synthesized has a triclinic symmetry with space group $P\bar 1$ and the unit cell parameters a=10.132 Å, b=9.385 Å, c=3.458 Å, α=105.443°, β=97.405°, γ=107.784°, and Z=1. At a temperature of 24.5 K, the crystal undergoes a magnetic phase transition to the magnetically ordered state. The assumption is made that the ferrimagnetic structure of the Cu₅Bi₂B₄O₁₄ crystal consists of two ferromagnetic sublattices coupled through the antiferromagnetic exchange interaction. The unit cell of the crystal contains five copper ions, of which one ion belongs to the first sublattice and the other four ions form the second sublattice. Analysis of the resonant and magnetic static properties demonstrates that the Cu₅Bi₂B₄O₁₄ crystal exhibits an easy-axis magnetic anisotropy. The direction of the easy axis coincides with the c axis of the crystal, whereas the a and b axes are the hard magnetic axes with saturation fields approximately equal to 25 and 10 kOe, respectively.     

New compounds in the Mn-X-Bi system where X = Ni, Cu, RhorPd

A new class of magnetic compounds has been discovered in the temary system Mn-X-Bi where X is Ni, Cu, Rh or Pd. The approximate compositions of these compounds are Mn₅Ni₂Bi₄, Mn₃Cu₄Bi₄, Mn₅Rh₂Bi₄, and Mn₅Pd₂Bi₄. The Bravais lattice is face-centered cubic, and the lattice constants are 12.16 Å (X = Ni), 12.18 Å (X = Cu), 12.31 Å (X = Rh) and 12.44 Å (X = Pd). These compounds are probably ferromagnetic and have Curie temperatures in the range -7°C to 183°C. A crystal structure is proposed for these compounds which contains 88 atoms/unit cell.     

Structural transformations of K<Subscript>3</Subscript>H(SO<Subscript>4</Subscript>)<Subscript>2</Subscript> crystals with variations in temperature

Single crystals of the K₃H(SO₄)₂ compound are investigated using X-ray diffraction on Xcalibur S and Bruker diffractometers. The structure of the low-temperature monoclinic phase is refined (space group C2/c, z = 4, a = 14.698(1) Å, b = 5.683(1) Å, c = 9.783(1) Å, β = 103.01(1)°, T = 293 K, Bruker diffractometer), the structural phase transition is revealed, and the structure of the high-temperature trigonal phase is determined (space group R \(\bar 3\) m, z = 3, a = 5.73(1) Å,c = 21.51(1) Å,T = 458 K, Xcalibur diffractometer).     

A Rule Governing Crystallization of Configurationally Directional Polymers: The Crystal Structure of the α and β Forms of Polypivalolactone

A “Rule” is proposed for incorporation of polymer chains having directional configuration, e.g. A‐B‐C‐A‐B‐C, into a crystal. Crystallization into a lamella morphology, as in slow crystallization from the melt, will incorporate antiparallel sequences (↑↓↑↓↑↓). Formation of a fiber by drawing the lamellar morphology must produce a different crystal structure containing parallel directional sequences. The drawn fiber must be polymorphic with a disordered aggregation of antiparallel and parallel crystal polymorphs. An example of this rule is found in the crystal structure of polypivalolactone. The melt crystallized α form is monoclinic, P2₁/c with a=9.05Å, b (fiber axis)=5.97Å, c=11.69Å, β=121.4° and consists of planar antiparallel sequences. The molecular conformation is a folded zig‐zag arrangement. On drawing a fiber, a disordered second phase of parallel plus antiparallel sequences is created. The chain conformation is a slightly distorted extended zigzag. The crystal structure of the directionally disordered β form is metrically monoclinic, with a=5.95Å, b=10.32Å, c (fiber axis)=4.94Å, β=101.3°. Examples of several classes of crystalline polymers demonstrating this Rule are presented.     

Ab initio and crystal field studies of the Mn4+-doped Ba2LaNbO6 double-perovskite

A detailed study using the ab initio DFT-based calculations of the electronic and optical properties of pure and Mn⁴⁺ doped Ba₂LaNbO₆ is presented in this paper. Comparison of the calculated electronic bands structure, density of states diagrams, and dielectric functions for the pure and doped crystal reveals the changes induced by the Mn⁴⁺ impurity ions. In addition, the energy levels of the Mn⁴⁺ ion in the ordered perovskite Ba₂LaNbO₆ are calculated by the exchange charge model (ECM) of crystal field theory and compared with the experimental data that has been presented in the literature. The calculated Mn⁴⁺ energy levels are in good agreement with the experimental spectra. Additionally, the excitation band shapes of the ⁴A_2g(⁴F)–⁴T_2g(⁴F) and ⁴A_2g(⁴F)–⁴T_1g(⁴F) transitions are modeled to estimate the zero-phonon lines (ZPL) positions and the effective number of phonons, which are involved in the corresponding excitation transition. The results of our calculations yield the crystal field parameter of Dq=1780 cm^?1 and Racah parameters B=670 and C=3290 cm^?1, with C/B=4.9 for the Mn⁴⁺ ion in the double-perovskite Ba₂LaNbO₆.     

A new molecular C60 complex with bis(methylenedithio)tetrathiafulvalene (BMDT-TTF): Synthesis, crystal structure, and properties

A new molecular C₆₀ complex of the composition (BMDT-TTF) · C₆₀ · 2CS₂ (I) with the bis(methylenedithio)tetrathiafulvalene (BMDT-TTF) organic donor is synthesized. The molecular and crystal structures of this complex are determined by x-ray diffraction. The (BMDT-TTF) · C₆₀ · 2CS₂ (I) compound crystallizes in a monoclinic crystal system. The main crystal data are as follows: a=13.550(5) Å, b=9.964(7) Å, c=17.125(8) Å, β=99.52(4)°, V=2280(2) ų, M=1229.45, and space group P2₁/m. Crystals of I have a layered structure: layers consisting of C₆₀ molecules alternate with layers composed of BMDT-TTF and CS₂ molecules. It is found that, in complex I, the donor and C₆₀ molecules are linked through the shortest contacts, which leads to a change in the molecular geometry of BMDT-TTF. The donor molecules in a crystal layer are characterized by the shortest S...S contacts. The IR data indicate the electroneutrality of the fullerene molecule. The electrical conductivity of (BMDT-TTF) · C₆₀ · 2CS₂ single crystals is measured using the four-point probe method at room temperature: σ_RT=2×10^?5 Ω^?1 cm^?1.     

NQR, NMR and Crystal Structure Studies of [C(NH2)3]2HgX4 (X = Br, I)

The crystal structure of [C(NH₂)₃]₂HgBr₄ has been determined at room temperature: monoclinic, space group C2/c, with a = 10.035(2), b = 11.164(2), c = 13.358(3) Å, β = 111.67(3)°, and Z = 4. The crystal consists of planar [C(NH₂)₃]⁺ and distorted tetrahedral [HgBr₄]^2? ions. The Hg atom is located on a two-fold axis such that two sets of inequivalent Br atoms exist in an [HgBr₄]^2? ion. In accordance with the crystal structure, two ⁸¹Br NQR lines widely separated in frequency were observed between 77 and ca. 380 K. [C(NH₂)₃]₂HgI₄ yielded four ¹²⁷I NQR lines ascribable to m = ±1/2 ? ±3/2 transitions, indicating that its crystal structure is different from the bromide complex. The ¹H NMR T ₁ measurements showed a single minimum for the bromide but two minima for the iodide. The analyses based on the C₃ reorientations of the planar [C(NH₂)₃]⁺ ions gave the activation energies of 29.8 kJ mol^?1 for the bromide, and 30.2 and 40.0 kJ mol^?1 for the iodide.     

Transmission Electron Microscopy Study of Polymorphism in Barium Gallate BaGa2O4

Polymorphism in barium gallate BaGa₂O₄ was studied using electron diffraction and high resolution electron microscopy. Three modifications of BaGa₂O₄ with structures closely related to the high-temperature α-form were observed. The phase transitions from γ-BaGa₂O₄ (a _γ = 18.6143(2) Å = 2<formula><radical><radicand>3</radicand></radical></formula>a _α, c _γ = 8.6544(1) Å = c _α, S.G. P6₃) to β-BaGa₂O₄ (a _β = 2a _α, c _β = c _α S.G. P6₃) and to the new δ-polymorph having a monoclinic structure (a _δ = c _α, b _δ = 2a _α + b _α, c _δ = 2b _α and β ≈ 92°, S.G. P2₁/c) were induced by electron beam irradiation. High resolution electron microscopy (HREM) observations allow to establish the close similarity between the structures of δ-BaGa₂O₄ and β-SrGa₂O₄. The γ→β and β→δ transitions involve a rearrangement of oxygen atoms in the BaO layers together with a tilting distortion of the tetrahedral framework. The microstructure of the δ-phase is characterised by the presence of numerous translation and orientation domains.