scholarly journals Crystal-Chemical Properties of Synthetic Almandine-Pyrope Solid Solution by X-Ray Single-Crystal Diffraction and Raman Spectroscopy

Crystals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 541 ◽  
Author(s):  
Kuang ◽  
Xu ◽  
Li ◽  
Ye ◽  
Huang ◽  
...  
Keyword(s):  
Solid Solution ◽  
Single Crystal ◽  
Cell Parameter ◽  
Chemical Properties ◽  
Unit Cell ◽  
Crystal Chemical ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Sio4 Tetrahedron ◽  
Crystal Unit Cell

Crystal-chemical properties of synthetic Almandine-Pyrope (Alm-Pyr) solid solutions were investigated by X-ray single-crystal diffraction and Raman spectroscopy. Garnet solid solution with different compositions were synthesized from powder at 4.0 GPa and annealed at 1200 °C for 48 h by a multi-anvil pressure apparatus. Garnet crystals with different sizes (about 60-1000 μm) were obtained from synthesis. The results of X-ray single-crystal diffraction show that the unit cell constants decrease with increasing Pyr contents in the synthetic Alm-Pyr crystals due to the smaller ionic radius of Mg2+ in eightfold coordination than that of Fe2+. The data exhibit obviously positive deviations from ideal mixing volumes across the Alm-Pyr join which may be caused by the distortion of the SiO4 tetrahedron. Moreover, the significant decrease in the average M-O bond length and volume of the [MgO8]/[FeO8] dodecahedron with increasing Pyr contents are the most important factors to the decrease in the Alm-Pyr crystal unit cell constant and volume. On the other hand, selected bond distances (average <M-O>, <Al-O>, and <D-O> distances) have a linear correlation with the unit-cell parameter, but the <Si-O> distance has nonlinear correlation. With increasing the unit-cell parameter, the average <M-O> distance increases significantly, followed by the average <D-O> and <Al-O> distances. While the <Si-O> distance changes negligibly further confirming the conclusion that the significant decrease of the average M-O bond length of the [MgO8]/[FeO8] dodecahedron with increasing Pyr contents are the most important factors to the decrease in the Alm-Pyr crystal unit cell volume. In the Raman spectra collected for the Alm-Pyr solid solutions, Raman vibration mode assignments indicate that the Raman vibrational spectra change along the Alm-Pyr binary solution. The mode frequencies of Si-O stretching, Si-O bending, and the rotation of the SiO4-tetrahedron (R(SiO4)) decrease linearly, while the translational modes of the SiO4-tetrahedron (T(SiO4)) increase with increasing Alm contents.

scholarly journals Minerály řady ullmannit - gersdorffit v asociaci s milleritem z haldy dolu Lill v Příbrami (Česká republika)

2020 ◽  
Vol 28 (1) ◽  
pp. 203-209
Author(s):  
Jiří Sejkora ◽  
Jakub Plášil ◽  
Jiří Špalek ◽  
Pavel Škácha
Keyword(s):  
Solid Solution ◽  
Czech Republic ◽  
Single Crystal ◽  
Unit Cell Parameter ◽  
Cell Parameter ◽  
Unit Cell ◽  
Ore Deposit ◽  
Metallic Luster ◽  
X Ray ◽  
Mine Dump

Minerals of the ullmannite–gersdorffite solid-solution was found at mine dump material from the Lill mine, the Černojamské ore deposit, Příbram, central Bohemia, Czech Republic. It forms grey groups of idiomorphic crystals up to 0.5 mm across with metallic luster on millerite crystals. It is strongly chemically zoned, from As-rich ullmannite to gersdorffite with variable Sb contents. Its unit-cell parameter, a 5.7728(13) Å and V 192.37(7) Å3, was refined from single-crystal X-ray data. Groups of acicular millerite crystals up to 4 mm in length and formula (Ni0.97Co0.03)Σ1.00S1.01 and very rare siegenite grains up to 80 μm and formula Co1.00(Ni1.66Co0.24Fe0.02)Σ1.92S4.09 were found in association.

Space-Group Determination of the Orthorhombic Form of NaV6O11

1995 ◽  
Vol 28 (5) ◽  
pp. 599-603 ◽  
Author(s):  
Y. Kanke ◽  
H. Shigematsu ◽  
K. Ohshima ◽  
K. Kato
Keyword(s):  
Phase Transition ◽  
Low Temperature ◽  
Single Crystal ◽  
Diffraction Study ◽  
Structural Phase ◽  
Unit Cell ◽  
Single Crystal Diffraction ◽  
Space Group ◽  
X Ray

The unit cell and space group of orthorhombic NaV6O11 (low-temperature form) are found by an X-ray single-crystal diffraction study at 300 K (hexagonal, P63/mmc), 100 K (hexagonal, P63 mc) and 20 K (orthorhombic). The orthorhombic form (o) shows no superstructure and its unit cell is related to the hexagonal one (h): a o ≃ a h + b h , a o ≃ −a h + b h and c o ≃ c h . Bijvoet-pair examination confirms that it crystallizes in the noncentrosymmetric space group Cmc21. The hexagonal (P63 mc)-orthorhombic (Cmc21) structural phase transition is proved to be of second order.

Crystal structure and crystal-chemical features of a new Ti-rich member of the eudialyte family

1999 ◽  
Vol 214 (5) ◽  
Author(s):  
R. K. Rastsvetaeva ◽  
A. P. Khomyakov ◽  
G. Chapuis
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Crystal Chemical ◽  
Single Crystal Diffraction ◽  
Eudialyte Group ◽  
X Ray ◽  
Trigonal Structure

AbstractThe trigonal structure of a new member of the eudialyte group was established from X-ray single-crystal diffraction,

Characterization of synthetic hedenbergite (CaFeSi2O6)–petedunnite (CaZnSi2O6) solid solution series by X-ray single crystal diffraction

2005 ◽  
Vol 32 (8-9) ◽  
pp. 552-563 ◽  
Author(s):  
Matthias Heuer ◽  
Alexandra L. Huber ◽  
Geoffrey D. Bromiley ◽  
Karl Thomas Fehr ◽  
Klaus Bente
Keyword(s):  
Solid Solution ◽  
Single Crystal ◽  
Solid Solution Series ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Solution Series

scholarly journals Synthesis, Structure, and Characterization of Keggin-Type Germanate

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Ya-feng Li ◽  
Xiao-lin Qin ◽  
Yue Xu ◽  
Wen-yuan Gao ◽  
Yue Gao
Keyword(s):  
Single Crystal ◽  
Elemental Analysis ◽  
Thermal Study ◽  
Unit Cell ◽  
Single Crystal Diffraction ◽  
Structural Water ◽  
X Ray ◽  
Keggin Type ◽  
Tetragonal System

A novel Keggin-type germanate, (NH4)9[Ge7O14F3]3·1.75H2O (I), is hydrothermally synthesized and structurally characterized by X-ray single-crystal diffraction, elemental analysis, XRD, and TG. (I) is tetragonal system with space group I4/mmm and unit cell:a=28.280(4) Å,c=24.881(5) Å,V=19899(6) Å3,Dc=1.632 g/cm3,μ(Mo Kα)=6.309 mm−1,Z=2,R1=0.1141for 2576 reflections withFo>2(Fo). Ge7O14F3entry is defined as the cluster including one octahedron, two edge-sharing triganol bipyramids, and four tetrahedra. Every Ge7O14F3entry links adjacent four Ge7O14F3entries by four tetrahedra. Twelve Ge7O14F3entries construct a cage with all octahedra of Ge7O14F3pointing inside, which can be simplified into Keggin-type cage through Ge7O14F3as the node. The solvent experiment proves that (I) is stable in the water and sensitive to base and acid. The result of XRD shows that the structural water of (I) is easily lost to drop the crystalline. The thermal study indicates that the Keggin-type cage of (I) begins to partly collapse at 200°C and finally changes into GeO2.

X-Ray Powder Structural Analysis of the Complexes of Benzo-15-Crown-5 with NaClO4 and KI: [C14H20O5]NaClO4 and [C14H20O5]2KI

1987 ◽  
Vol 2 (2) ◽  
pp. 99-101
Author(s):  
G. Shoham ◽  
N. Cohen ◽  
S. Schneider ◽  
I. Mayer
Keyword(s):  
Crown Ether ◽  
Single Crystal ◽  
Diffraction Analysis ◽  
Powder Diffraction ◽  
Unit Cell ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Crystal System ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

AbstractX-ray powder diffraction analysis of the complex of Benzo-15-Crown-5 (B-15-Crown-5) with NaClO4 displays a monoclinic crystal system with refined unit cell parameters of a = 8.829(3)Å, b = 8.327(3)Å, c = 24.21(2)Å, ß = 99.18(1)Å, V = 1757.1(1)Å3, Z = 4, and Dx = 1.48 g/cm3. The space group, P21/c, and the unit cell dimensions, determined by a single crystal diffraction analysis, agree well with those of the powder analysis. X-ray powder diffraction analysis of the complex of B-15-Crown-5 with KI displays a tetragonal crystal system with refined unit cell dimensions of a = b = 17.869(3)Å, c = 9.761(3)Å, V = 3116.7(1)Å3, Z = 4, and Dx = 1.50 g/cm3. The space group, P4/n, and the unit cell dimensions, determined by a single crystal diffraction analysis, agree well with those of die powder diffraction analysis. The powder and single crystal analyses of the two complexes indicate that in the solid phase, B-15-Crown-5 forms a 1:1 complex with Na+ and a 2:1 complex with K+. The variation in the complexation mode of B-15-Crown-5 with different cations, partially explains the lack of selectivity of this crown ether towards Na+, while from considerations of the cavity size alone this crown ether was expected to be considerably selective towards this cation.

Crystal structure and thermal chemical properties of 2-(2,4-dimethylanilino)-3-methyl-6-diethylaminofluorane

2006 ◽  
Vol 60 (3) ◽  
Author(s):  
X. Li ◽  
C. Ding ◽  
B. Tian ◽  
Q. Liu ◽  
S. Zhang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Chemical Properties ◽  
Diffraction Method ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Triclinic System

AbstractThe crystal structure of 2-(2,4-dimethylanilino)-3-methyl-6-diethylaminofluorane has been determined by single crystal X-ray diffraction method. The crystal belongs to triclinic system, space group P-1 with unit cell constants a = 11.2877(9) Å, b = 11.9539(9) Å, c = 12.2365(9) Å, α = 97.2580(10)°, β = 116.2850(10)°, γ = 106.3710(10)°, V = 1358.48(18) Å 3, Z = 2, D c = 1.234 g/cm3, μ = 0.079 mm−1, F(000) = 536, R and w(R) are 0.0718 and 0.2055, respectively, for 5239 unique reflections with 3745 observed reflections (I > 2σ(I)).

scholarly journals Environmentally Friendly Nafion-Catalyzed Synthesis of Substituted 2-Ethyl-3-Methylquinolines from Aniline and Propionaldehyde under Microwave Irradiation

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 877
Author(s):  
Chieh-Kai Chan ◽  
Chien-Yu Lai ◽  
Cheng-Chung Wang
Keyword(s):  
Reaction Mechanism ◽  
Microwave Irradiation ◽  
Single Crystal ◽  
Diffraction Analysis ◽  
Environmentally Friendly ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Related Data ◽  
Heating Source ◽  
Chemical Structures

Herein, we report a facile synthetic methodology for the preparation of 2,3-dialkylquinolines from anilines and propionaldehydes. This cyclization involved environmentally friendly Nafion® NR50 as an acidic catalyst with microwave irradiation as the heating source. A series of substituted 2-ethyl-3-methylquinolines were prepared from various anilines and propionaldehyde derivatives through this protocol with good to excellent yields. Some new chemical structures were confirmed by X-ray single-crystal diffraction analysis and the related data were provided. The plausible reaction mechanism studies are also discussed.

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