scholarly journals Structural, thermal, and IR studies of β-[Nd2O2](CrO4), an unexpected analog of a slag phase [Ba2F2](S6+O3S2−)

2019 ◽  
Vol 234 (1) ◽  
pp. 1-8
Author(s):  
Dmitri O. Charkin ◽  
Igor V. Plokhikh ◽  
Anastasiya I. Zadoya ◽  
Aleksandr N. Zaloga ◽  
Wulf Depmeier ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Transition Metal ◽  
Slag Phase ◽  
Interlayer Space ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ir Studies ◽  
Space Size ◽  
Structural Architecture ◽  
New Compounds

Abstract A family of Ln2CrO6 (Ln=Pr, Nd, Sm–Tb) compounds has been re-investigated using powder X-ray diffraction and IR spectroscopy. The structure of β-Nd2CrO6≡β-[Nd2O2](CrO4) is similar to that of the slag compound [Ba2F2](S6+O3S2−) in that it exhibits a disordered arrangement of (CrO4)2− anions between [Nd2O2]2+ litharge-type blocks. Its structural architecture is also related to other layered α- and γ-[Ln2O2](AO4) species (A=S, Cr, Mo), showing various orientations of the tetrahedral anions within the interlayer space. Size relationships between the incorporated tetrahedral anions and formation of different structure types (denoted as M1-, M2- and T-type) are reviewed. The possible existence of new compounds which are isostructural with, or structurally related to, β-[Nd2O2](CrO4) and bearing other transition metal-centred tetrahedral anions are discussed.

Evolution structurale de la nacrite en fonction de la nature des molécules organiques intercalees

2000 ◽  
Vol 33 (6) ◽  
pp. 1351-1359 ◽  
Author(s):  
A. Ben Haj Amara ◽  
H. Ben Rhaiem ◽  
A. Plançon
Keyword(s):  
Ir Spectroscopy ◽  
Hydrogen Bonds ◽  
Dimethyl Sulfoxide ◽  
Organic Molecules ◽  
Interlayer Space ◽  
X Ray Diffraction ◽  
X Ray ◽  
Intercalated Compounds ◽  
Xrd Study ◽  
Intercalation Process

Nacrite has been intercalated with two polar organic molecules: dimethyl sulfoxide (DMSO) andN-methylacetamide (NMA). The homogeneous nacrite complexes have been studied by X-ray diffraction (XRD) and infrared (IR) spectroscopy. The XRD study is based on a comparison between experimental and calculated patterns. The structures of the intercalated compounds have been determined, including the mutual positions of the layers after intercalation and the positions of the intercalated molecules in the interlayer space. It has been shown that the intercalation process causes not only a swelling of the interlayer space but also a shift in the mutual in-plane positions of the layers. This shift depends on the nature of the intercalated molecules and is related to their shape and the hydrogen bonds which are established with the surrounding surfaces. For a given molecule, the intercalation process is the same for the different polytypes of the kaolinite family. These XRD results are consistent with those of IR spectroscopy.

Three 3D Metal-Organic Frameworks Constructed from Keggin Polyanions and Multi-nuclear AgI Clusters: Assembly, Structures and Properties

2013 ◽  
Vol 68 (7) ◽  
pp. 778-788 ◽  
Author(s):  
Xiu-Li Wang ◽  
Na Li ◽  
Ai-Xiang Tian ◽  
Jun Ying ◽  
Guo-Cheng Liu ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Metal Organic Frameworks ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Structures And Properties ◽  
Elemental Analyses ◽  
Metal Organic ◽  
New Compounds ◽  
Inorganic Ligands

Three Keggin-based metal-organic frameworks (MOFs) containing multi-nuclear silver subunits, [Ag7(ptz)5(H2O)2][H2SiMo12O40] (1), [Ag8(ptz)5(H2O)2][AsW12O40] (2) and [Ag7(ptz)5(H2O)][HAsMo12O40] (3) (ptzH=5-(4-pyridyl)-tetrazole), have been synthesized under hydrothermal conditions by changing the inorganic polyanions. The new compounds have been characterized by elemental analyses, TG analyses, IR spectroscopy, and single-crystal X-ray diffraction. In compound 1, the multi-nuclear Ag5(ptz)5 subunits are interconnected to form chains, which are further linked by AgI cations to construct a 3D MOF with large channels. Pairs of SiMo12O404- polyanions reside in the channels as penta-dentate inorganic ligands. In 2, six AgI cations link five ptz- anions to construct a hexa-nuclear subunit [Ag6(ptz)5]+, which is interconnected to form chains. These chains are further linked by AgI cations to construct a 3D MOF, where AsW12O403- polyanions reside as hexa-dentate ligands. Compound 3exhibits a 3D MOF based on Ag5(ptz)5 subunits, in which the hexa-dentate AsMo12O403- polyanions are incorporated. The rigid tetrazole-based ligand ptz- plays an important role in the formation of the multi-nuclear subunits of the title compounds. The electrochemical properties of compound 1and the photocatalytic properties of compounds 1and 3have been investigated.

SrRhIn2, SrPdIn2, SrIrIn2, and SrPtIn2 – New Intermetallic Compounds with a Filled Variant of the CaIn2 Structure

1999 ◽  
Vol 54 (1) ◽  
pp. 38-44 ◽  
Author(s):  
Rolf-Dieter Hoffmann ◽  
Ute Ch. Rodewald ◽  
Rainer Pöttgen
Keyword(s):  
Transition Metal ◽  
High Frequency ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bonding Analysis ◽  
Metal Bonding ◽  
Metal Atoms ◽  
Transition Metal Atoms ◽  
New Compounds ◽  
Transition Metal Bonding

SrRhIn2, SrPdIn2, Srlrln2, and SrPtIn2 have been synthesized by reaction of mixtures of the elements in glassy carbon crucibles in a high-frequency furnace. The new compounds were investigated by X-ray diffraction on powders as well as single crystals; a = 437.3(2), b = 1091.9(5), c = 798.0(2) pm for SrRhln2, a = 453.54(7), b = 1079.8(2), c = 790.4(1) pm for SrPdIn2, a = 434.83(8),b= 1102.6(2) ,c = 798.6(2) pm for Srlrln2, a = 447.5( 1) , b = 1091.0(3), c = 787.6( 1) pm for SrPtIn2. They adopt the MgCuAl2 structure, a ternary ordered version of Re3B. Chemical bonding analysis leads to the description of a filled Srln2 structure in which the In-in-bonding is modified by the insertion of transition metal atoms into the planar strontium layers, thus favoring strong indium-transition metal bonding.

Studies on the Preparation, Characterization and Solubility of -Cyclodextrin-Roxythromycin Inclusion Complexes

2009 ◽  
Vol 2 (2) ◽  
pp. 523-530
Author(s):  
D. Nagasamy Venkatesh ◽  
S. Karthick ◽  
M. Umesh ◽  
G. Vivek ◽  
R.M. Valliappan ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Inclusion Complexes ◽  
Phase Solubility ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ir Studies ◽  
Poorly Soluble ◽  
Poorly Soluble Drug

Roxythromycin/ β-cyclodextrin (Roxy/ β-CD) dispersions were prepared with a view to study the influence of β-CD on the solubility and dissolution rate of this poorly soluble drug. Phase-solubility profile indicated that the solubility of roxythromycin was significantly increased in the presence of β-cyclodextrin and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Physical characterization of the prepared systems was carried out by differential scanning calorimetry (DSC), X-ray diffraction studies (XRD) and IR studies. Solid state characterization of the drug β-CD binary system using XRD, FTIR and DSC revealed distinct loss of drug crystallinity in the formulation, ostensibly accounting for enhancement of dissolution rate.

Preparation, properties and structure of some intermediate nido- and arachno-monocarbaboranes

1981 ◽  
Vol 46 (10) ◽  
pp. 2345-2353 ◽  
Author(s):  
Karel Baše ◽  
Bohumil Štíbr ◽  
Jiří Dolanský ◽  
Josef Duben
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Nmr Spectra ◽  
Liquid Ammonia ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Starting Compound

The 6-N(CH3)3-6-CB9H11 carbaborane reacts with sodium in liquid ammonia with the formation of 6-CB9H12- which was used as a starting compound for preparing the 4-CB8H14, 9-L-6-CB9H13 (L = (CH3)2S, CH3CN and P(C6H5)3), 1-(η5-C5H5)-1,2-FeCB9H10-, and 2,3-(η5-C5H5)2-2,31-Co2CB9H10- carboranes. The 4-CB8H14 compound was dehydrogenated at 623 K to give 4-(7)-CB8H12 carborane. Base degradation of 6-N(CH3)3-6-CB9H11 in methanol resulted in the formation of 3,4-μ-N(CH3)3CH-B5H10. The structure of all compounds was proposed on the basis of their 11B and 1H NMR spectra and X-ray diffraction was used in the case of the transition metal complexes.

Hydrolytic products of Fe(III) after oxidation of Fe(II) by chlorate

1982 ◽  
Vol 47 (4) ◽  
pp. 1069-1077 ◽  
Author(s):  
Karel Mádlo ◽  
František Hanousek ◽  
Antonín Petřina ◽  
Jaroslav Tláskal
Keyword(s):  
Electron Microscopy ◽  
Ir Spectroscopy ◽  
Chemical Analysis ◽  
Ferrous Sulphate ◽  
Reaction Medium ◽  
Potassium Chlorate ◽  
X Ray Diffraction ◽  
X Ray

Ferrous sulphate was oxidized by potassium chlorate in the pH region 2-7 and at temperatures ranging from 298.1 to 323.1 K and various hydrolytic products of Fe(III) were separated and indentified. The separated solid ferric products were analyzed using a combination of the chemical analysis, IR spectroscopy, X-ray diffraction, and electron microscopy. The following substances were found as major components of the products: Fe2O3.n H2O ("ferric gel"), Fe2O3.n H2O with bound SO2-4 ions ("sulphogel"), α-FeO(OH), γ-FeO(OH) and Fe3O4. Their amount depends particularly on the pH temperature of the reaction medium.

scholarly journals High-pressure synthesis of REB5O8(OH)2 (RE = Ho, Er, Tm)

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Michael Zoller ◽  
Hubert Huppertz
Keyword(s):  
High Pressure ◽  
Rare Earth ◽  
Ir Spectroscopy ◽  
Earth Metal ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Solution ◽  
Pressure Synthesis ◽  
The Rare Earth

AbstractThe rare earth oxoborates REB5O8(OH)2 (RE = Ho, Er, Tm) were synthesized in a Walker-type multianvil apparatus at a pressure of 2.5 GPa and a temperature of 673 K. Single-crystal X-ray diffraction data provided the basis for the structure solution and refinement. The compounds crystallize in the monoclinic space group C2 (no. 5) and are composed of a layer-like structure containing dreier and sechser rings of corner sharing [BO4]5− tetrahedra. The rare earth metal cations are coordinated between two adjacent sechser rings. Further characterization was performed utilizing IR spectroscopy.

scholarly journals Exploring the Structural Chemistry of Pyrophosphoramides: N,N′,N″,N‴-Tetraisopropylpyrophosphoramide

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 149-163
Author(s):  
Duncan Micallef ◽  
Liana Vella-Zarb ◽  
Ulrich Baisch
Keyword(s):  
Crystal Structure ◽  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Hydrogen Bonding ◽  
Nmr Spectroscopy ◽  
Ir Spectroscopy ◽  
Room Temperature ◽  
Intermolecular Hydrogen Bonding ◽  
X Ray Diffraction ◽  
X Ray

N,N′,N″,N‴-Tetraisopropylpyrophosphoramide 1 is a pyrophosphoramide with documented butyrylcholinesterase inhibition, a property shared with the more widely studied octamethylphosphoramide (Schradan). Unlike Schradan, 1 is a solid at room temperature making it one of a few known pyrophosphoramide solids. The crystal structure of 1 was determined by single-crystal X-ray diffraction and compared with that of other previously described solid pyrophosphoramides. The pyrophosphoramide discussed in this study was synthesised by reacting iso-propyl amine with pyrophosphoryl tetrachloride under anhydrous conditions. A unique supramolecular motif was observed when compared with previously published pyrophosphoramide structures having two different intermolecular hydrogen bonding synthons. Furthermore, the potential of a wider variety of supramolecular structures in which similar pyrophosphoramides can crystallise was recognised. Proton (1H) and Phosphorus 31 (31P) Nuclear Magnetic Resonance (NMR) spectroscopy, infrared (IR) spectroscopy, mass spectrometry (MS) were carried out to complete the analysis of the compound.

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