X-Ray Diffraction and IR Spectrum for Activated Surface Hydrolysis of Al Metal into AlO(OH)·αH2O Nanocrystals in a New Monoclinic Crystal Structure

2001 ◽  
Vol 157 (1) ◽  
pp. 40-49 ◽  
Author(s):  
S. Rana ◽  
S. Ram
Keyword(s):  
Crystal Structure ◽  
Ir Spectrum ◽  
X Ray Diffraction ◽  
Monoclinic Crystal ◽  
X Ray ◽  
Monoclinic Crystal Structure ◽  
Hydrolysis Of ◽  
Activated Surface

Preparation, Crystal Structure, and Properties of the Lanthanoid Carbides Ln4C7 with Ln = Ho, Er, Tm, and Lu

1996 ◽  
Vol 51 (5) ◽  
pp. 646-654 ◽  
Author(s):  
Ralf Czekalla ◽  
Wolfgang Jeitschko ◽  
Rolf-Dieter Hoffmann ◽  
Helmut Rabeneck
Keyword(s):  
Crystal Structure ◽  
Rietveld Method ◽  
Magnetic Ordering ◽  
Monoclinic Crystal ◽  
X Ray ◽  
Neutron Powder Diffraction Data ◽  
Monoclinic Crystal Structure ◽  
Arc Melting ◽  
Structure Factors ◽  
Hydrolysis Of

The isotypic carbides Ln4C7 (Ln = Ho, Er, Tm, Lu) were prepared by arc-melting of the elemental components, followed by annealing at 1300 °C. The positions of the metal and of some carbon atoms of the monoclinic crystal structure of LU4C7 were determined from X-ray powder data, and the last carbon positions were found and refined from neutron powder diffraction data: P21/c, a = 360.4(1), b = 1351.4(3), c = 629.0(2) pm, β = 104.97(2)°, Z = 2, R = 0.026 for 429 structure factors and 15 positional parameters. The structure contains isolated carbon atoms with octahedral lutetium coordination and linear C3-units, with C-C bond lengths of 132(1) and 135(1) pm. This carbide may therefore be considered as derived from methane and propadiene. The hydrolysis of LU4C7 with distilled water yields mainly methane and propine, while the hydrolyses of the corresponding holmium and erbium carbides resulted in relatively large amounts of saturated and unsaturated C2-hydrocarbons in addition to the expected products methane and propine. The structure comprises two-dimensionally infinite NaCl-type building elements, which are separated by the C3-units. It may be described as a stacking variant of a previously reported structure of HO4C7, now designated as the a-modification. The Lu4C7-type β -modification was obtained at higher temperatures. Its structure was refined by the Rietveld method from X-ray powder data to a residual R = 0.037 for 320 F values and 15 positional parameters. Lu4C7 is Pauli paramagnetic; β -HO4C7 and Er4C7 show Curie-Weiss behavior with magnetic ordering temperatures of less than 20 K.

scholarly journals A new crystalline form of αβ-D-lactose prepared by oven drying a concentrated aqueous solution of D-lactose

2019 ◽  
Vol 75 (7) ◽  
pp. 904-909 ◽  
Author(s):  
Daniel Nicholls ◽  
Carole Elleman ◽  
Norman Shankland ◽  
Kenneth Shankland
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Three Dimensional ◽  
Crystalline Form ◽  
X Ray Diffraction ◽  
Monoclinic Crystal ◽  
X Ray ◽  
Monoclinic Crystal Structure ◽  
High Degree ◽  
Triclinic Form

A new crystalline form of αβ-D-lactose (C12H22O11) has been prepared by the rapid drying of an approximately 40% w/v syrup of D-lactose. Initially identified from its novel powder X-ray diffraction pattern, the monoclinic crystal structure was solved from a microcrystal recovered from the generally polycrystalline mixed-phase residue obtained at the end of the drying step. This is the second crystalline form of αβ-D-lactose to be identified and it has a high degree of structural three-dimensional similarity to the previously identified triclinic form.

AsPh4[W(O)Cl3(HN3S2)]; Synthese, IR-Spektrum und Kristallstruktur / AsPh4[W(O)Cl3(HN3S2)]; Synthesis, IR Spectrum and Crystal Structure

1986 ◽  
Vol 41 (1) ◽  
pp. 48-52 ◽  
Author(s):  
Elke Conradi ◽  
Heribert Wadle ◽  
Ulrich Müller ◽  
Kurt Dehnicke
Keyword(s):  
Crystal Structure ◽  
Ir Spectrum ◽  
Crystal Packing ◽  
Partial Hydrolysis ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
X Ray ◽  
Distorted Octahedral ◽  
Oxo Ligand ◽  
Hydrolysis Of

Violet crystals of AsPh4[W(O)Cl3(HN3S2)] were obtained by partial hydrolysis of AsPh4[WCl4(N3S2)] in a saturated solution in CH2Cl2/CCl4. Its IR spectrum is reported. The crystal structure was determined by X-ray diffraction (2284 independent observed reflexions, R = 0.041). Crystal data: triclinic, space group P1̄, Z = 2, a = 812.2, b = 1268.4, c = 1343.9 pm, α = 88.58, β = 82.04 and γ = 88.26°. The compound consists of AsPh4⊕ cations and [W(O)Cl3(HN3S2)⊖ anions in which the tungsten atoms have a distorted octahedral coordination with one oxo-ligand (171 pm), three chlorine atoms and two nitrogen atoms of the planar (HN3S7)2⊖ ligand. The WN bond lengths are 183 and 226 pm; the longer WN bond is due to the hydrogen atom attached to its N atom and to the trans influence of the oxo group. The crystal packing corresponds to one of the types frequently found among tetraphenylphosphonium compounds with cations stacked to parallel columns.

Effects of Glycine on the Properties of the Long Afterglow Phosphor CaAl2O4:Eu2+, Nd3+ Prepared by Combustion Synthesis

2011 ◽  
Vol 396-398 ◽  
pp. 284-287
Author(s):  
Xiao Xia Liu ◽  
Hai Lian Qin ◽  
Gui Hua Peng ◽  
Zhen Hua Liang
Keyword(s):  
Crystal Structure ◽  
Combustion Synthesis ◽  
Luminescent Properties ◽  
Combustion Products ◽  
X Ray Diffraction ◽  
Monoclinic Crystal ◽  
X Ray ◽  
Long Afterglow ◽  
Monoclinic Crystal Structure ◽  
Afterglow Time

The long afterglow phosphor CaAl2O4: Eu2+, Nd3+ was prepared by combustion synthesis, and the influence of glycine on the luminescent properties of the long afterglow phosphor was studied. The samples were characterized by X-ray diffraction (XRD) and fluorescence spectroscopy (PL) etc. The results showed that the main phase of the combustion products is CaAl2O4 with monoclinic crystal structure. The introduction of glycine prolongs the afterglow time.

Synthesis, IR spectrum, thermal behaviour and crystal structure of a novel one-dimensional cyano-bridged zinc(II)/nickel(II) complex

2005 ◽  
Vol 220 (1) ◽  
Author(s):  
Ahmet Karadag ◽  
Hümeyra Pasaoglu ◽  
Gökhan Kastas ◽  
Orhan Büyükgüngör
Keyword(s):  
Crystal Structure ◽  
Thermal Analysis ◽  
Coordination Polymer ◽  
Single Crystal ◽  
Ir Spectrum ◽  
Polymeric Chain ◽  
X Ray Diffraction ◽  
Bimetallic Complex ◽  
One Dimensional ◽  
X Ray

AbstractThe cyano-bridged heteronuclear coordination polymer of zinc(II)/nickel(II) has been prepared by N-(2-hydroxyethyl)-ethylendiamine (hydet-en), alternatively named 2-(2-aminoethylamino)-ethanol and characterised by IR and thermal analysis. In the bimetallic complex, the decomposition of hydet-en ligands is seen to be endothermic whereas that of the cyano ligands is found to be exothermic. The crystal structure of the complex has been determined by single-crystal X-ray diffraction. The crystal structure of the zinc(II)-nickel(II) complex consists of a one-dimensional polymeric chain –Zn(hydet-en)

Crystal Structure and Vibrational Behaviour of Aqua Di(saccharinato)di(nicotinamide)copper(II)

2002 ◽  
Vol 57 (1) ◽  
pp. 43-46 ◽  
Author(s):  
Beatriz S. Parajón-Costaa ◽  
Enrique J. Baran ◽  
Oscar E. Piro ◽  
Eduardo E Castellano
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Ir Spectrum ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray

The crystal structure of [Cu(sac)2(nic)2(H2O)] (sac = saccharinate anion; nic = nicotinamide) has been determined by single-crystal X-ray diffraction. It crystallizes in the monoclinic space group C2/c with Z = 4 and the Cu(II) ion presents a CuN4O square pyramidal coordination. Some comparisons with related structures are made and the most important features of its IR spectrum were also discussed.

Electron density, disorder and polymorphism: high-resolution diffraction studies of the highly polymorphic neuralgic drug carbamazepine

2016 ◽  
Vol 72 (1) ◽  
pp. 39-50 ◽  
Author(s):  
Ioana Sovago ◽  
Matthias J. Gutmann ◽  
Hans Martin Senn ◽  
Lynne H. Thomas ◽  
Chick C. Wilson ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Resolution ◽  
Diffraction Data ◽  
Structural Formula ◽  
Orthorhombic Crystal ◽  
Monoclinic Crystal ◽  
Orthorhombic Crystal Structure ◽  
Space Group ◽  
X Ray ◽  
Monoclinic Crystal Structure

Analysis of neutron and high-resolution X-ray diffraction data on form (III) of carbamazepine at 100 K using the atoms in molecules (AIM) topological approach afforded excellent agreement between the experimental results and theoretical densities from the optimized gas-phase structure and from multipole modelling of static theoretical structure factors. The charge density analysis provides experimental confirmation of the partially localized π-bonding suggested by the conventional structural formula, but the evidence for any significant C—N π bonding is not strong. Hirshfeld atom refinement (HAR) gives H atom positional and anisotropic displacement parameters that agree very well with the neutron parameters. X-ray and neutron diffraction data on the dihydrate of carbemazepine strongly indicate a disordered orthorhombic crystal structure in the space groupCmca, rather than a monoclinic crystal structure in space groupP21/c. This disorder in the dihydrate structure has implications for both experimental and theoretical studies of polymorphism.

[ η6-C6Me6Fe- η5-C5H5]2Fe2Cl6 · 2 CH2Cl2: Bildung und Kristallstruktur / [η6-C6Me6Fe-η5-C5H5]2Fe2Cl6· 2CH2Cl2: Formation and Crystal Structure

1992 ◽  
Vol 47 (8) ◽  
pp. 1075-1078 ◽  
Author(s):  
Karin Ruhlandt-Senge ◽  
Ulrich Müller
Keyword(s):  
Crystal Structure ◽  
Ir Spectrum ◽  
Title Compound ◽  
The Novel ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray

When hexymethylbenzene-cyclopentadienyl-iron reacts with ozone in dichloromethane, the title compound is one of the products. Its crystal structure was determined by X-ray diffraction (R = 0.145 for 1412 unique reflexions). Crystal data: a = 1815.1(8), b = 1314.8(5), c = 1823.0(8) pm, space group Pbca, Z = 8. The sandwich-like [η6-C6Me6Fe-η5-C5H5]+ ions exhibit large thermal motions, and the CH2C12 molecules are disordered in two orientations. The novel [Fe2Cl6]2- ion has the structure of two tetrahedra sharing an edge. Its IR spectrum is reported.

scholarly journals Synthesis, Characterization, and Crystal Structure of Negundoside (2′-p-Hydroxybenzoyl Mussaenosidic Acid)

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Suresh Sharma ◽  
B. D. Gupta ◽  
Rajni Kant ◽  
Vivek K. Gupta
Keyword(s):  
Crystal Structure ◽  
Room Temperature ◽  
Direct Method ◽  
Monoclinic Crystal System ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Monoclinic Crystal ◽  
Full Matrix ◽  
X Ray ◽  
Cell Parameters

The structure of title compound Negundoside (2′-p-hydroxybenzoyl mussaenosidic acid) was established by spectral and X-ray diffraction studies. The compound crystallizes in the monoclinic crystal system with space group P21 having unit cell parameters: a=11.6201 (5) Å, b=9.2500 (4) Å, c=12.2516 (5) Å, β=97.793 (4)°, and Z=2. The crystal structure was solved by direct method using single crystal X-ray diffraction data collected at room temperature and refined by full-matrix least-squares procedures to a final R value of 0.0520 for 3389 observed reflections.

Magnetic Structure and Properties of the Intercalated Compound Fe0.5TiSe2

2010 ◽  
Vol 168-169 ◽  
pp. 157-160 ◽  
Author(s):  
N.V. Baranov ◽  
N.V. Selezneva ◽  
Valery G. Pleshchev ◽  
N.V. Mushnikov ◽  
V.I. Maksimov
Keyword(s):  
Magnetic Field ◽  
Crystal Structure ◽  
Electrical Resistivity ◽  
Neutron Diffraction ◽  
Magnetic Moments ◽  
Structure And Properties ◽  
Monoclinic Crystal ◽  
X Ray ◽  
Monoclinic Crystal Structure ◽  
A Value

The intercalated compound Fe0.5TiSe2 has been studied by means of X-ray, neutron diffraction, electrical resistivity and magnetization measurements. This compound with Fe atoms located between Se-Ti-Se sandwiches has a monoclinic crystal structure and exhibits a long-range antiferromagnetic (AF) ordering below TN = 135 K. At T < TN, the Fe magnetic moments with a value ~ 3.0 µB are directed at an angle of (74.4±0.5)º to the layers and form a tilted antiferromagnetic structure with the propagation vector (½, 0, ½). It has been shown that application of magnetic field above 300 kOe may lead to transformations of the AF structure.

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