scholarly journals Pickeringite from the Stone Town Nature Reserve in Ciężkowice (the Outer Carpathians, Poland)

Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 187 ◽  
Author(s):  
Mariola Marszałek ◽  
Adam Gaweł ◽  
Adam Włodek
Keyword(s):  
Solid Solutions ◽  
Nature Reserve ◽  
Low Ph ◽  
Mineral Waters ◽  
Unit Cell Parameters ◽  
Monoclinic System ◽  
Sulfate Ions ◽  
Cell Parameters ◽  
Outer Carpathians ◽  
Lattice Modes

Pickeringite, ideally MgAl2(SO4)4·22H2O, is a member of the halotrichite group minerals XAl2(SO4)4·22H2O that form extensive solid solutions along the joints of the X = Fe-Mg-Mn-Zn. The few comprehensive reports on natural halotrichites indicate their genesis to be mainly the low-pH oxidation of pyrite or other sulfides in the Al-rich environments of weathering rock-forming aluminosilicates. Pickeringite discussed here occurs within the efflorescences on sandstones from the Stone Town Nature Reserve in Ciężkowice (the Polish Outer Carpathians), being most probably the first find on such rocks in Poland. This paper presents mineralogical and geochemical characteristics of the pickeringite (based on SEM-EDS, XRPD, EPMA and RS methods) and suggests its possible origin. It belongs to the pickeringite–apjohnite (Mg-Mn joints) series and has the calculated formula Mg0.75Mn0.21Zn0.02Cu0.01Al2.02(S0.99 to 1.00O4)4·22H2O (based on 16O and 22H2O). The unit cell parameters refined for the monoclinic system space group P21/c are: a = 6.1981(28) Å, b= 24.2963(117) Å, c = 21.2517(184) Å and β = 100.304(65)°. The Raman spectra (SO4) bands are the intensive 994 cm−1 and a low-intensive 975 cm−1 (ν1), low-intensive 1081, 1123 and 1145 cm−1 (ν3), 524, 467 and 425cm−1 (ν2), 615 cm−1 (ν4), while those at 344 and 310 cm−1 are attributed to νg H2O and at 223 cm−1 to the lattice modes. Crystallization of pickeringite within the particular tor resulted from a certain set of conditions: climatic (e.g., season, temperature, humidity), physicochemical (e.g., pH, concentration), mineral (the presence of pyrite), and site-related (location and efflorescence protection). The sulfate ions could have been derived from oxidation of pyrite in the Ciężkowice sandstones and possibly are related to local mineral waters.

Structural Study of a new Compound Based on Acid 1,4-Cyclohexanedicarboxylic (1,4-CDC)

2010 ◽  
Vol 6 (1) ◽  
pp. 891-896
Author(s):  
Manel Halouani ◽  
M. Dammak ◽  
N. Audebrand ◽  
L. Ktari
Keyword(s):  
Aqueous Solution ◽  
Water Molecules ◽  
Carboxyl Group ◽  
X Ray Diffraction ◽  
Compound I ◽  
Unit Cell Parameters ◽  
Monoclinic System ◽  
X Ray ◽  
Cell Parameters ◽  
Cyclohexanedicarboxylic Acid

One nickel 1,4-cyclohexanedicarboxylate coordination polymers, Ni2 [(O10C6H4)(COO)2].2H2O  (I), was hydrothermally synthesized from an aqueous solution of Ni (NO3)2.6H2O, (1,4-CDC) (1,4-CDC = 1,4-cyclohexanedicarboxylic acid) and tetramethylammonium nitrate. Compound (I) crystallizes in the monoclinic system with the C2/m space group. The unit cell parameters are a = 20.1160 (16) Å, b = 9.9387 (10) Å, c = 6.3672 (6) Å, β = 97.007 (3) (°), V= 1263.5 (2) (Å3) and Dx= 1.751g/cm3. The refinement converged into R= 0.036 and RW = 0.092. The structure, determined by single crystal X-ray diffraction, consists of two nickel atoms Ni (1) and Ni (2). Lots of ways of which is surrounded by six oxygen atoms, a carboxyl group and two water molecules.

Structure and properties of solid solutions in the Mg-Al-B system

Open Physics ◽  
2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Ludmila Sevastyanova ◽  
Olga Gulish ◽  
Vladimir Stupnikov ◽  
Vladimir Genchel ◽  
Oleg Kravchenko ◽  
...  
Keyword(s):  
Solid Solutions ◽  
Unit Cell ◽  
Superconducting Transition ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Resistivity Measurements ◽  
Ceramic Synthesis

AbstractCompounds with the general formula Mg1−x AlxB2 were obtained by two-step ceramic synthesis. All compounds were characterized by X-ray diffraction, NMR spectroscopy, and by four point probe resistivity measurements in various magnetic fields method. The diborides unit cell parameters were determined as a function of the Al mole fraction. With the vaues of x up to 0.40 (where x is the composition of the stock prepared for sintering), the unit cell parameters of Mg1−x AlxB2 are similar to those of pure MgB2 and the superconducting transition temperature was lowered. For stock compositions of 0:25 ≤ x ≤ 0:60, the products contain a superstructure, also superconducting phase, which becomes the only product at x = 0:50, and at x > 0:60 this phase is replaced by AlB2-based solid solutions.

Microstructure and Properties of Lead-Free Perovskite Ceramics on the Base of KNN Perovskite

2020 ◽  
Vol 27 ◽  
pp. 90-98
Author(s):  
E.D. Politova ◽  
G.M. Kaleva ◽  
Alexander V. Mosunov ◽  
N.V. Sadovskaya ◽  
Dmitry A. Kiselev ◽  
...  
Keyword(s):  
Solid Solutions ◽  
Piezoelectric Coefficient ◽  
Piezoelectric Properties ◽  
Unit Cell ◽  
Lead Free ◽  
Unit Cell Parameters ◽  
Ionic Radii ◽  
Cell Parameters ◽  
Microstructure And Properties ◽  
Perovskite Ceramics

The influence of LiSbO3 on the structure, microstructure, dielectric, ferroelectric and local piezoelectric properties of (K0.5Na0.5)NbO3 ceramics has been studied. Changes in unit cell parameters correlated with ionic radii changes and high effective local d33 piezoelectric coefficient values were observed depending on solid solutions compositions.

scholarly journals Crystal Structure of Bovine Alpha-Chymotrypsin in Space Group P65

Crystals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 460 ◽  
Author(s):  
Andrew Marshall ◽  
Benjamin Keiller ◽  
Jordan Pederick ◽  
Andrew Abell ◽  
John Bruning
Keyword(s):  
Crystal Structure ◽  
Crystal Lattice ◽  
Ammonium Sulphate ◽  
Serine Proteases ◽  
Protein Crystallization ◽  
Model System ◽  
Low Ph ◽  
Unit Cell Parameters ◽  
Space Group ◽  
Cell Parameters

Chymotrypsin is a protease that is commonly used as a standard for protein crystallization and as a model system for studying serine proteases. Unliganded bovine α-chymotrypsin was crystallized at neutral pH using ammonium sulphate as the precipitant, resulting in crystals that conform to P65 symmetry with unit cell parameters that have not been reported previously. Inspection of crystallographic interfaces revealed that the major interface between any two molecules in the crystal lattice represents the interface of the biological dimer, as previously observed for crystals of unliganded α-chymotrypsin grown at low pH in space group P21.

Synthesis and X-ray diffraction data of 2-ethyl-6-(pyridin-4-yl)-7H-indeno[2,1-c]quinoline

2013 ◽  
Vol 29 (1) ◽  
pp. 53-57
Author(s):  
H.A. Camargo ◽  
A. Sánchez ◽  
J.A. Henao ◽  
Arnold R. Romero Bohórquez ◽  
Vladimir V. Kouznetsov
Keyword(s):  
Elemental Sulfur ◽  
Cycloaddition Reaction ◽  
Unit Cell ◽  
Gas Chromatography Mass Spectrometry ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Monoclinic System ◽  
X Ray ◽  
Cell Parameters ◽  
Xrpd Pattern

The compound 2-ethyl-6-(pyridin-4-yl)-7H-indeno[2,1-c]quinoline (2) (chemical formula C23H22N2) was synthesized through the free-solvent oxidation reaction mediated by elemental sulfur from the corresponding 2-ethyl-6-(pyridin-4-yl)-5,6,6a,11b-tetrahidro-7H-indeno[2,1-c]quinoline (1), an adduct easily obtained, using the Lewis acid-promoted [4 + 2] cycloaddition reaction. Preliminary molecular characterization was performed by Fourier transform-infrared and gas chromatography-mass spectrometry. The X-ray powder diffraction (XRPD) pattern for the title compound was analyzed and found to be crystallized in monoclinic system, space groupP21/n(N° 14) with refined unit-cell parametersa = 20.795 (8) Å,b = 7.484 (2) Å,c = 10.787 (2) Å andß = 93.96° (2). The volume of the unit cell isV = 1674.8 (6) Å3.

Structure analysis of CaTi1−xSnxO3 (x = 0.0–1.0) solid solutions

2014 ◽  
Vol 29 (3) ◽  
pp. 254-259 ◽  
Author(s):  
Naoki Takani ◽  
Hisanori Yamane
Keyword(s):  
Solid State ◽  
Solid Solutions ◽  
Solid State Reaction ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Diffraction Patterns ◽  
Perovskite Type ◽  
Perovskite Type Structure

CaTi1−xSnxO3 (x = 0.0–1.0) solid solutions were prepared by solid-state reaction at 1450 °C. Rietveld refinement of their powder X-ray diffraction patterns revealed that all the solid solutions crystallized in orthorhombic cells with the perovskite-type structure, the space group Pbnm. The refined unit-cell parameters linearly increased with nominal tin contents x.

scholarly journals Crystal structure of gluconate 5-dehydrogenase from Lentibacter algarum

2020 ◽  
Vol 76 (5) ◽  
pp. 228-234
Author(s):  
Dengke Tian ◽  
Xueqi Fu ◽  
Wenqiang Cao ◽  
Hong Yuan
Keyword(s):  
Crystal Structure ◽  
Escherichia Coli ◽  
Structural Similarity ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
Monoclinic System ◽  
Space Group ◽  
Cell Parameters ◽  
High Structural Similarity

Gluconate 5-dehydrogenase (Ga5DH; EC 1.1.1.69) from Lentibacter algarum (LaGa5DH) was recombinantly expressed in Escherichia coli and purified to homogeneity. The protein was crystallized and the crystal structure was solved at 2.1 Å resolution. The crystal belonged to the monoclinic system, with space group P1 and unit-cell parameters a = 55.42, b = 55.48, c = 79.16 Å, α = 100.51, β = 105.66, γ = 97.99°. The structure revealed LaGaDH to be a tetramer, with each subunit consisting of six α-helices and three antiparallel β-hairpins. LaGa5DH has high structural similarity to other Ga5DH proteins, demonstrating that this enzyme is highly conserved.

scholarly journals Synthesis, Crystal Structure and IR Spectrum studies of 2-(4-Methyl-2-phenyl-4,5-dihydro-oxazol-4-ylmethyl)- isoindole-1,3-dione

2019 ◽  
Vol 9 (2) ◽  
pp. 116-124 ◽  
Author(s):  
Alami Anouar ◽  
Khadim Dioukhane ◽  
Younas Aouine ◽  
Mohamed El Omari ◽  
Lahcen El Ammari ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Least Squares Method ◽  
Spectroscopic Studies ◽  
Amino Compound ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Monoclinic System ◽  
X Ray ◽  
Cell Parameters ◽  
Complete Matrix

The organo-amino compound of title 2-(4-methyl-2-phenyl-4,5-dihydro-oxazol-4-ylmethyl)-isoindole-1,3-dione was synthesized by the mixture of (4-methyl-2-phenyl-4,5-dihydrooxazol-4-yl)methyl-4-methylbenzenesulfonate and isoindoline-1,3-dione in N,N-dimethylformamide with a yield of around 65%. The structural study of the compound, C19H16N2O3, is realized using single crystal X-Ray diffraction which shows that this compound crystallizes in the monoclinic system (P21/c, Z = 4) with the unit cell parameters: a = 14.3728 (13) Ã…, b = 9.6829 (10) Ã…, c = 11.8964 (12) Ã… and β = 107.384 (3). The refinement of the structure by the least-squares method with complete matrix leads to the following reliability factors R/Rw are 0.044/0.130.In the crystal, the molecules are linked together by hydrogen bonds and π…π interactions.The Infrared spectroscopic studies show the bands confirming the presence of the groups C=O, C-O, C-N, -CH3, -CH2 and =CH. 

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