The crystal-chemistry of Vietnamese talcs from the Thanh Son district (Phu Tho province, Vietnam)

Clay Minerals ◽  
2015 ◽  
Vol 50 (5) ◽  
pp. 607-617 ◽  
Author(s):  
Angela Dumas ◽  
François Martin ◽  
The Ngo Ke ◽  
Hanh Nguyen Van ◽  
Dung Nguyen Viet ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Nuclear Magnetic Resonance ◽  
Crystal Chemistry ◽  
Industrial Applications ◽  
Crystal Chemical ◽  
Chemical Analyses ◽  
X Ray Diffraction ◽  
Ore Deposit ◽  
X Ray ◽  
Wide Range

AbstractThe mineralogy and crystal chemistry of a new talc ore deposit situated at Thu Ngac commune, Thanh Son district, Phu Tho province, Vietnam, was investigated using X-ray fluorescence, electron microprobe, X-ray diffraction, Fourier transform infrared spectroscopy, solid-state nuclear magnetic resonance (29Si and1H) and colorimetry.Both chemical and crystal-chemical analyses showed that the talcs from the Phu Tho province are very pure because they contain few accessory minerals (chlorite, amphibole and goethite) and few substitutions of Si by Fe and Al in their crystal structure. The talc ore may well meet the standards required for a wide range of industrial applications.

scholarly journals Crystal Chemical Relations in the Shchurovskyite Family: Synthesis and Crystal Structures of K2Cu[Cu3O]2(PO4)4 and K2.35Cu0.825[Cu3O]2(PO4)4

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 807
Author(s):  
Ilya V. Kornyakov ◽  
Sergey V. Krivovichev
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Structural Complexity ◽  
Crystal Chemical ◽  
X Ray Diffraction ◽  
Complexity Measures ◽  
X Ray ◽  
The Family ◽  
Similarities And Differences ◽  
Related Compounds

Single crystals of two novel shchurovskyite-related compounds, K2Cu[Cu3O]2(PO4)4 (1) and K2.35Cu0.825[Cu3O]2(PO4)4 (2), were synthesized by crystallization from gaseous phase and structurally characterized using single-crystal X-ray diffraction analysis. The crystal structures of both compounds are based upon similar Cu-based layers, formed by rods of the [O2Cu6] dimers of oxocentered (OCu4) tetrahedra. The topologies of the layers show both similarities and differences from the shchurovskyite-type layers. The layers are connected in different fashions via additional Cu atoms located in the interlayer, in contrast to shchurovskyite, where the layers are linked by Ca2+ cations. The structures of the shchurovskyite family are characterized using information-based structural complexity measures, which demonstrate that the crystal structure of 1 is the simplest one, whereas that of 2 is the most complex in the family.

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.

scholarly journals Discovery of Fe7O9: a new iron oxide with a complex monoclinic structure

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Ryosuke Sinmyo ◽  
Elena Bykova ◽  
Sergey V. Ovsyannikov ◽  
Catherine McCammon ◽  
Ilya Kupenko ◽  
...  
Keyword(s):  
Applied Sciences ◽  
Crystal Structure ◽  
Iron Oxide ◽  
Iron Oxides ◽  
Industrial Applications ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Pressure High Temperature ◽  
Insight Into

Abstract Iron oxides are fundamentally important compounds for basic and applied sciences as well as in numerous industrial applications. In this work we report the synthesis and investigation of a new binary iron oxide with the hitherto unknown stoichiometry of Fe7O9. This new oxide was synthesized at high-pressure high-temperature (HP-HT) conditions, and its black single crystals were successfully recovered at ambient conditions. By means of single crystal X-ray diffraction we determined that Fe7O9 adopts a monoclinic C2/m lattice with the most distorted crystal structure among the binary iron oxides known to date. The synthesis of Fe7O9 opens a new portal to exotic iron-rich (M,Fe)7O9 oxides with unusual stoichiometry and distorted crystal structures. Moreover, the crystal structure and phase relations of such new iron oxide groups may provide new insight into the cycling of volatiles in the Earth’s interior.

The crystal structure of gatehouseite

2011 ◽  
Vol 75 (6) ◽  
pp. 2823-2832
Author(s):  
P. Elliott ◽  
A. Pring
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Three Dimensional ◽  
Direct Methods ◽  
Chemical Analyses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Manganese Phosphate ◽  
Phosphate Mineral ◽  
Unit Formula

AbstractThe crystal structure of the manganese phosphate mineral gatehouseite, ideally Mn52+(PO4)2(OH)4, space group P212121, a = 17.9733(18), b = 5.6916(11), c = 9.130(4) Å, V= 933.9(4) Å3, Z = 4, has been solved by direct methods and refined from single-crystal X-ray diffraction data (T = 293 K) to an R index of 3.76%. Gatehouseite is isostructural with arsenoclasite and with synthetic Mn52+(PO4)2(OH)4. The structure contains five octahedrally coordinated Mn sites, occupied by Mn plus very minor Mg with observed <Mn—O> distances from 2.163 to 2.239 Å. Two tetrahedrally coordinated P sites, occupied by P, Si and As, have <P—O> distances of 1.559 and 1.558 Å. The structure comprises two types of building unit. A strip of edge-sharing Mn(O,OH)6 octahedra, alternately one and two octahedra wide, extends along [010]. Chains of edge- and corner-shared Mn(O,OH)6 octahedra coupled by PO4 tetrahedra extend along [010]. By sharing octahedron and tetrahedron corners, these two units form a dense three-dimensional framework, which is further strengthened by weak hydrogen bonding. Chemical analyses by electron microprobe gave a unit formula of (Mn4.99Mg0.02)Σ5.01(P1.76Si0.07(As0.07)Σ2.03O8(OH)3.97.

Al analogue of chayesite from a lamproite of Cancarix, SE Spain, and its crystal structure

2020 ◽  
Vol 196 (3) ◽  
pp. 193-198
Author(s):  
Natalia V. Zubkova ◽  
Nikita V. Chukanov ◽  
Christof Schäfer ◽  
Konstantin V. Van ◽  
Igor V. Pekov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Diffraction Data ◽  
Empirical Formula ◽  
Structure Refinement ◽  
Crystal Chemical ◽  
Chemical Formula ◽  
Crystal Chemical Formula ◽  
X Ray Diffraction ◽  
Se Spain ◽  
X Ray

Al analogue of chayesite (with Al > Fe3+) was found in a lamproite from Cancarix, SE Spain. The mineral forms green thick-tabular crystals up to 0.4 mm across in cavities. The empirical formula derived from EMP measurements and calculated on the basis of 17 Mg + Fe + Al + Si apfu is (K0.75 Na0.20 Ca0.11)Mg3.04 Fe0.99 Al1.18 Si11.80 O30. The crystal structure was determined from single crystal X-ray diffraction data ( R = 2.38%). The mineral is hexagonal, space group P 6/ mcc, a = 10.09199(12), c = 14.35079(19) Å, V = 1265.78(3) Å3, Z = 2. Fe is predominantly divalent. Al is mainly distributed between the octahedral A site and the tetrahedral T 2 site. The crystal chemical formula derived from the structure refinement is C (K0.73 Na0.16 Ca0.11)B (Na0.02)4 A(Mg0.42 Al0.29 Fe0.29)2 T 2(Mg0.71 Fe0.16 Al0.13)3 T 1(Si0.985 Al0.015)12 O30.

Therman Expansion and Crystal Chemistry of (Sr1−x , K2x )Zr4(PO4)6 Ceramic

1995 ◽  
Vol 28 (5) ◽  
pp. 508-512 ◽  
Author(s):  
D.-M. Liu ◽  
L.-J. Lin ◽  
C.-J. Chen
Keyword(s):  
Crystal Structure ◽  
Grain Size ◽  
Thermal Expansion ◽  
High Temperature ◽  
Crystal Chemistry ◽  
X Ray Diffraction ◽  
Lattice Thermal Expansion ◽  
X Ray ◽  
Thermal Expansion Anisotropy ◽  
Sufficient Degree

Thermal expansion of (Sr1−x , K2x )Zr4(PO4)6 (SrKZP) (with x = 0–1) ceramic was investigated using both a dilatometer and a high-temperature X-ray diffractometer. The coefficients of thermal expansion (CTEs) of the SrKZP ceramic measured by the dilatometer demonstrate a similar trend as those from high-temperature X-ray diffraction. Both measurements show an ultra-low CTE at x = 0.5; nevertheless, this composition shows significant lattice thermal-expansion anisotropy (TEA), while the minimum TEA appears with composition x = 0.2. Although it possessed a sufficient degree of TEA, the x = 0.5 composition showed no visible microcracks or negligible microcracks over a grain size as large as 15 μm. A transition of space group from R{\bar 3} to R{\bar 3}c with composition between x = 0.3 and x = 0.5 has been observed. The crystal structure of the SrKZP ceramic with possible occupations of strontium and/or potassium within the lattice in relation to their influence on the CTEs is proposed.

Wickenburgite, a double-layer silicate Pb3Al[6][Ca[6]Al[4]Si[4]10O27(H2O)3]·H2O: Crystal chemistry and thermal behaviour

2003 ◽  
Vol 218 (8) ◽  
Author(s):  
K.-F. Hesse ◽  
F. Liebau ◽  
H.-H. Eulert
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Water Content ◽  
Crystal Chemistry ◽  
Diffraction Data ◽  
Thermal Analyses ◽  
Layer Silicate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ir Spectroscopic

AbstractTo clarify discrepancies in the literature with regard to the water content and crystal structure of wickenburgite, chemical and thermal analyses and IR spectroscopic measurements were made and the structure was redetermined with single-crystal X-ray diffraction data. It was found that the idealised composition of the mineral is PbPbWith regard to crystal structure, that described by Lam et al. is found to be essentially correct, except for an additional H

scholarly journals Linarite from the Ag-Pb ore deposit at Kletné near Suchdol nad Odrou (Jeseníky Culm, Vítkov Highlands)

2016 ◽  
Vol 65 (1) ◽  
pp. 88-96 ◽  
Author(s):  
Vladimír Hrazdil ◽  
Stanislav Houzar ◽  
Jiří Sejkora ◽  
Šárka Koníčková ◽  
Lenka Jarošová
Keyword(s):  
Raman Spectroscopy ◽  
Chemical Composition ◽  
Chemical Analyses ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Ore Deposit ◽  
X Ray ◽  
Cell Parameters ◽  
Copper Sulfides ◽  
Dark Blue

Abstract Linarite, PbCu2+(SO4)(OH)2, and associated minerals were studied at new locality near Kletné, where they occur in dump material of historic Ag-Pb mines exploited during the 16th century. Linarite forms thin blue coatings and tiny dark blue crystals (<1 mm in size) in small cavities, in assemblage with cerussite, brochantite and supergene copper sulfides. Mineral was identified by chemical analyses (electron microprobe), Raman spectroscopy and powder X-ray diffraction analysis. Chemical composition of the studied linarite can be expressed by empirical formula Pb0.98Cu1.06(SO4)Σ0.96(OH)2.15 and its refined unit-cell parameters are: a = 9.6944(3), b = 5.6499(2), c = 4.6846(1) Å, ß = 102.669(3)° and V = 250.50(1) Å3. Linarite formed together with other supergene minerals in the oxidation zone of the deposit by weathering of Pb- and Cu-sulphides.

Syntheses and Electrochemical Properties of [C5Me5Ru]+ Complexes with Polycyclic Arenes. Crystal Structure of[(C5Me5)Ru( μ6-chrysene)]PF6 · 0.5 Me2CO

1990 ◽  
Vol 45 (5) ◽  
pp. 658-666 ◽  
Author(s):  
Ivonne Chavez ◽  
Andrés Cisternas ◽  
Margarita Otero, ◽  
Enrique Román ◽  
Ulrich Müller
Keyword(s):  
Crystal Structure ◽  
Reduction Potential ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wide Range ◽  
Benzene Rings ◽  
Thermal Vibrations ◽  
Subsequent Addition ◽  
Mononuclear Compounds ◽  
C Nmr

Mononuclear and binuclear compounds [(C5Me5)Ru(η6-arene)PF6 and [(C5Me5Ru)2(η6,η6-arene)](PF6)2 were prepared by reacting (C5Me5)RuCl2, the arene and silver acetate with subsequent addition of NH4PF6, for arene = phenanthrene, chrysene, triphenylene, fluorene, bifluorene, biphenyl and 4,4′-biphenyl. The mononuclear compounds were also prepared for arene = naphthalene, anthracene, pyrene and coronene. The 1H and 13C NMR spectra are reported. By cyclic voltammetry all compounds show a first reduction potential that is considerably more positive compared with the free arene. The first cathodic wave is irreversible for a wide range of scanning speeds. However, the mononuclear coronene and the binuclear phenanthrene compounds show reversibility. The crystal structure of [(C5Me5)Ru(η6-chrysene)]PF6·0.5 Me2CO was determined by X-ray diffraction (3797 unique observed reflexions, R = 0.098). Crystal data: a = 1689.2(2), b = 1524.0(8), c = 2263.5(3) pm, β= 107.22(1)°, space group P21/n, Ζ = 8. Crystallographically independent, two cations [(C5Me5)Ru(η6-chrysene)]+ and two anions PF6- are present, but their structures are essentially equal. The [C5Me5Ru]+ unit is bonded to one of the terminal benzene rings of the chrysene in a sandwich manner; the rings bonded to Ru are nearly coplanar. The PF6- ions and the C5Me5 rings exhibit strong thermal vibrations.

A comparative X-ray diffraction, Mössbauer and NMR spectroscopic study of the vermiculites from Béni Bousera, Morocco and Palabora, Republic of South Africa

Clay Minerals ◽  
2002 ◽  
Vol 37 (2) ◽  
pp. 367-376 ◽  
Author(s):  
R. Badreddine ◽  
D. Vandormael ◽  
A. -M. Fransolet ◽  
G. J . Long ◽  
W. E. E. Stone ◽  
...  
Keyword(s):  
South Africa ◽  
Nuclear Magnetic Resonance ◽  
Nmr Spectra ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Chemical Analyses ◽  
X Ray Diffraction ◽  
Tetrahedral Sheet ◽  
X Ray ◽  
Angle Spinning

AbstractFive vermiculite samples collected from Béni Bousera, Morocco and four from Palabora, South Africa were investigated by X-ray diffraction, chemical analysis, 57Fe Mössbauer spectroscopy, and 27Al magic angle spinning nuclear magnetic resonance. The X-ray diffraction studies indicate that all vermiculites have very similar crystallographic parameters. The chemical analyses and the NMR spectra indicate that the Béni Bousera vermiculites contain Al3+ cations in both octahedral and tetrahedral sheets and the Palabora vermiculites contain Al3+ in the tetrahedral sheet. The Mössbauer spectra indicate that the Béni Bousera vermiculites contain more Fe2+ cations than the Palabora vermiculites and do not contain tetrahedral Fe3+ cations. The different cation compositions and distribution in the two sets of vermiculites may result from different parent minerals, i.e. chlorite in the case of Béni Bousera and phlogopite in the case of Palabora, and different genetic processes, i.e. weathering in Béni Bousera and hydrothermal alteration in Palabora.

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