Crystal Structure, Thermoanalytical Properties and Infrared Spectra of Double Magnesium Selenates

1996 ◽  
Vol 61 (9) ◽  
pp. 1295-1306 ◽  
Author(s):  
Zdeněk Mička ◽  
Lucie Prokopová ◽  
Ivana Císařová ◽  
David Havlíček
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Hydrogen Bonds ◽  
X Ray Diffraction ◽  
X Ray ◽  
Double Salts ◽  
Hydrogen Bond System ◽  
Bond System ◽  
Thermoanalytical Studies ◽  
Thermal Stability Of

Magnesium selenates double salts K2Mg(SeO4)2.6H2O, Rb2Mg(SeO4)2.6H2O, Cs2Mg(SeO4)2.6H2O, and (NH4)2Mg(SeO4)2.6H2O have been studied by means of X-ray diffraction methods, thermoanalytical methods, and infrared spectroscopy. The basic building units of these compounds are slightly deformed tetrahedra of selenate anions and octahedra of hexaaquamagnesium(II) cations interconnected by a system of hydrogen bonds. The investigation of IR spectra has been used in the discussion of X-ray diffraction results in the field of description of the hydrogen bond system and deformation of the basic polyhedra of selenate anion and hexaaquamagnesium cation. The thermoanalytical studies are used in evaluating the effects of hydrogen bonds and polarization influence of M+ cations on thermal stability of the compounds studied.

scholarly journals A New 3D Coordination Polymer of Bismuth with Nicotinic AcidN-Oxide

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Farzin Marandi ◽  
Ingo Pantenburg ◽  
Gerd Meyer
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Coordination Polymer ◽  
Three Dimensional ◽  
Water Molecules ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Thermal Stability Of

The new three-dimensional coordination polymer {[Bi(NNO)2(NO3)]·1.5H2O}n(1, NNO−= nicotinateN-oxide) was synthesized and characterized by elemental analysis, IR and1H-NMR spectroscopy, as well as single-crystal X-ray diffraction analysis.1crystallizes in the monoclinic space group C2/c. The crystal structure consists of a rectangular-shaped grid constructed with NNO linkers. Cavities of a diameter of 7.9–8.3 Å2are filled with disordered water molecules. The thermal stability of the compound was evaluated by thermogravimetric analysis.

X-ray data, optical anisotropism, and thermal stability of cobaltite, gersdorffite, and ullmannite

1969 ◽  
Vol 37 (285) ◽  
pp. 26-33 ◽  
Author(s):  
P. Bayliss
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Cell Size ◽  
Large Cell ◽  
Structure Type ◽  
X Ray Diffraction ◽  
Compositional Zoning ◽  
Cubic Symmetry ◽  
X Ray ◽  
Thermal Stability Of

SummaryData are presented from cobaltite (CoAsS), gersdorffite (NiAsS), and ullmannite (NiSbS) for cell size, compositional zoning, mineralogical association, X-ray diffraction powder intensities, and optical anisotropy. The presence of powder X-ray diffraction reflections 001 and 011 are related to the crystal structure type. The amount of distortion from cubic symmetry is related to the 001 reflection intensity and also to the optical anisotropism strength. These properties are related approximately to the thermal stability of the distorted crystal structure. This thermal stability increases with the substitution of cobalt for nickel, which decreases the cell size. An order-disorder change occurs before the distortion release in non-cubic gersdorffite (P1) with a large cell size, whereas only a distortion release is observed in cobaltite (Pca21) and non-cubic gersdorffite (P1) with a small cell size. Glaucodot (Co,Fe)AsS converted to cobaltite at 620 C. No evidence was found to relate optical anisotropism of pyrite to deviations from cubic symmetry.

Supramolecular Complex Formed by Fumaric Acid and Piperazine: Crystal Structure, and Synthon Cooperation

2015 ◽  
Vol 1120-1121 ◽  
pp. 168-173
Author(s):  
Shi Ying Wang ◽  
Pei Qi Xing ◽  
Xiu Juan Geng ◽  
Rui Xin Chen
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Fumaric Acid ◽  
Binding Sites ◽  
Supramolecular Complex ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrogen Bond Interactions ◽  
Supramolecular Chains ◽  
Thermal Stability Of

A new molecular complex constructed by fumaric acid with piperazine has been prepared and characterized by single crystal X-ray diffraction. The number of fumaric acid involved in the complex equals to the number of N-protonated binding sites in the piperazine molecule. The structure contained infinite 1D supramolecular chains held together by robust, primary O–H•••O charge-assisted hydrogen bonds, and the 2D sheet like pattern constructed via the expected carboxyl-piperazine heterosynthon. Persistent N–H•••O interactions were found to play an important role in the formation of the final 3D arrays. The five dominant supramolecular synthons in the crystal structure are the heteromeric carboxylic acid•••piperazine hydrogen bond interactions, which prevail in the presence of widely differing chemical functionalities. Thermal stability of the compound has been investigated by thermogravimetric analysis (TGA) of mass loss.

Intercalated 2D+2D hydrogen-bonded sheets in co-crystals of cobalt salt with 1H,1′H-[3,3′]bipyridinyl-6,6′-dione

2020 ◽  
Vol 98 (7) ◽  
pp. 347-351
Author(s):  
Midhun Mohan ◽  
Love Karan Rana ◽  
Thierry Maris ◽  
Adam Duong
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Metal Salt ◽  
Supramolecular Organization ◽  
Cobalt Salt ◽  
X Ray Diffraction ◽  
Phase Purity ◽  
Crystalline Sample ◽  
X Ray ◽  
Thermal Stability Of

Co-crystals of Co(II) salt and 1H,1′H-[3,3′]bipyridinyl-6,6′-dione 1 with the composition 1·Co(CHOO)2(H2O)4 were obtained by mixing both reactants. The single-crystal structure reveals that the metal salt and organic ratio is 1:1. The supramolecular organization of the two components in the co-crystal was mainly dictated by hydrogen bonds between 1 and Co(II) complex. Infrared and powder X-ray diffraction were used to confirm the homogeneity and the phase purity of the bulk crystalline sample of 1·Co(CHOO)2(H2O)4. TGA/DTA was recorded to evaluate the thermal stability of the co-crystals.

Structure refinement, hydrogen-bond system and vibrational spectroscopy of hohmannite, Fe3+2[O(SO4)2]·8H2O

2015 ◽  
Vol 79 (1) ◽  
pp. 11-24 ◽  
Author(s):  
G. Ventruti ◽  
G. Della Ventura ◽  
R. Orlando ◽  
F. Scordari
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Vibrational Spectroscopy ◽  
Structural Model ◽  
Structure Refinement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrogen Bond System ◽  
Bond System ◽  
First Time

AbstractThe crystal structure of hohmannite, Fe3+2[O(SO4)2]·8H2O, was studied by means of single-crystal X-ray diffraction (XRD) and vibrational spectroscopy. The previous structural model was confirmed, though new diffraction data allowed the hydrogen-bond system to be described in greater and more accurate detail.Ab initiocalculations were performed in order to determine accurate H positions and to support the experimental model obtained from XRD data. Infrared and Raman spectra are presented for the first time for this compound and comments are made on the basis of the crystal structure and the known literature for sulfate minerals.

scholarly journals Crystal structure of 3-benzyl-2-[(E)-2-(furan-2-yl)ethenyl]-2,3-dihydroquinazolin-4(1H)-one and 3-benzyl-2-[(E)-2-(thiophen-2-yl)ethenyl]-2,3-dihydroquinazolin-4(1H)-one from synchrotron X-ray diffraction

2018 ◽  
Vol 74 (1) ◽  
pp. 10-14
Author(s):  
Flavien A. A. Toze ◽  
Vladimir P. Zaytsev ◽  
Lala V. Chervyakova ◽  
Elisaveta A. Kvyatkovskaya ◽  
Pavel V. Dorovatovskii ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Axial Position ◽  
Isatoic Anhydride ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Angles ◽  
Pyramidal Geometry ◽  
Three Component Reaction ◽  
Racemic Crystals

The chiral title compounds, C21H18N2O2, (I), and C21H18N2OS, (II) – products of the three-component reaction between benzylamine, isatoic anhydride and furyl- or thienyl-acrolein – are isostructural and form isomorphous racemic crystals. The tetrahydropyrimidine ring in (I) and (II) adopts a sofa conformation. The amino N atom has a trigonal–pyramidal geometry [sum of the bond angles is 347.0° for both (I) and (II)], whereas the amido N atom is flat [sum of the bond angles is 359.3° for both (I) and (II)]. The furyl- and thienylethenyl substituents in (I) and (II) are planar and the conformation about the bridging C=C bond isE. These bulky fragments occupy the axial position at the quaternary C atom of the tetrahydropyrimidine ring, apparently, due to steric reasons. In the crystals, molecules of (I) and (II) form hydrogen-bonded helicoidal chains propagating along [010] by strong intermolecular N—H...O hydrogen bonds.

Formation and Thermal Stability of Nd0.32Y0.68Si1.7 Layers Formed by Channeled Ion Beam Synthesis

1998 ◽  
Vol 514 ◽  
Author(s):  
M. F. Wu ◽  
A. Vantomne ◽  
S. Hogg ◽  
H. Pattyn ◽  
G. Langouche ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Ion Beam ◽  
Hexagonal Structure ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Good Crystalline Quality ◽  
Ion Beam Synthesis ◽  
Thermal Stability Of

ABSTRACTThe Nd-disilicide, which exists only in a tetragonal or an orthorhombic structure, cannot be grown epitaxially on a Si(111) substrate. However, by adding Y and using channeled ion beam synthesis, hexagonal Nd0.32Y0.68Si1.7 epilayers with lattice constant of aepi = 0.3915 nm and cepi = 0.4152 nm and with good crystalline quality (χmin of Nd and Y is 3.5% and 4.3 % respectively) are formed in a Si(111) substrate. This shows that the addition of Y to the Nd-Si system forces the latter into a hexagonal structure. The epilayer is stable up to 950 °C; annealing at 1000 °C results in partial transformation into other phases. The formation, the structure and the thermal stability of this ternary silicide have been studied using Rutherford backscattering/channeling, x-ray diffraction and transmission electron microscopy.

Study of Thermal Behaviour of EPDM/SBR Blends and Carbon Nanocoatings Deposited by Sputtering

2021 ◽  
Vol 875 ◽  
pp. 116-120
Author(s):  
Muhammad Alamgir ◽  
Faizan Ali Ghauri ◽  
Waheed Qamar Khan ◽  
Sajawal Rasheed ◽  
Muhammad Sarfraz Nawaz ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Weight Loss ◽  
Thermogravimetric Analysis ◽  
Thermal Behavior ◽  
Thermal Behaviour ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Stability Of

In this study, the effect of SBR concentration (10 Phr, 20 Phr & 30 Phr ) on the thermal behavior of EPDM/SBR blends was studied. Thermogravimetric analysis (TGA) was used to check weight loss of samples as function of temperature by heating upto 600°C. X-ray diffraction (XRD) was performed to determine quality and % crystallinity of the elastomer blends. It was seen that % crystallinity improved with an increase in the content of SBR in EPDM/SBR blends. TGA revealed that the thermal stability of EPDM/SBR blends has improved by 17% than neat EPDM. Carbon nano-coatings produced by sputtering have no beneficial influence on thermal behaviour of elastomers.

Syntheses, Crystal Structures and Thermal Stability of Co(II) and Zn(II) Complexes with Ethyl Carbazate

2005 ◽  
Vol 60 (5) ◽  
pp. 505-510 ◽  
Author(s):  
Tong-Lai Zhang ◽  
Jiang-Chuang Song ◽  
Jian-Guo Zhang ◽  
Gui-Xia Ma ◽  
Kai-Bei Yu
Keyword(s):  
Thermal Stability ◽  
Aqueous Solutions ◽  
Diffraction Analysis ◽  
Single Crystals ◽  
Slow Evaporation ◽  
X Ray Diffraction ◽  
Element Analysis ◽  
Thermal Stabilities ◽  
X Ray ◽  
Thermal Stability Of

Cobalt(II) and zinc(II) complexes of ethyl carbazate (ECZ), [Co(ECZ)3](NO3)2 and [Zn(ECZ)3] (NO3)2, were synthesized. Single crystals of these two compounds were grown from aqueous solutions using a slow evaporation method. Their structures have been determined by X-ray diffraction analysis. Both of them are monoclinic with space group P21/n. The complexes are further characterized by element analysis and IR measurements. Their thermal stabilities are studied by using TG-DTG, DSC techniques. When heated to 350 °C, only metal oxide was left for both complexes.

Synthesis, crystal structure and molecular conformation of (±)-1-oxoferruginol and (±)-shonanol

2004 ◽  
Vol 219 (10) ◽  
Author(s):  
Swastik Mondal ◽  
Monika Mukherjee ◽  
Arnab Roy ◽  
Debabrata Mukherjee
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Diffraction Data ◽  
Molecular Conformation ◽  
Membered Ring ◽  
Methyl Groups ◽  
Single Bond ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chemical Structures

Abstract(±)-1-oxoferruginol and (±)-shonanol, two potential intermediates in the synthesis of tricyclic diterpenoid ferruginol, have been prepared and crystal structures of the compounds have been investigated using single-crystal X-ray diffraction data. The methyl groups of the isopropyl moiety in (±)-shonanol are disordered over two positions with occupation factors 0.65(1) and 0.35(1), respectively. Although the chemical structures of two compounds are very similar, a C—C single bond in the terminal six-membered ring of (±)-1-oxoferruginol is replaced by a C=C bond in (±)-shonanol, the quantitative isostructurality index calculations indicate that the structures are not isostructural. Intermolecular O—H…O hydrogen bonds between pairs of molecules in the compounds related by center of inversion lead to characteristic dimers forming R

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