The crystal-structure and optical properties of matlockite (PbFCl)

1934 ◽  
Vol 23 (146) ◽  
pp. 587-597 ◽  
Author(s):  
F. A. Bannister
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Chemical Composition ◽  
Chemical Analysis ◽  
Single Crystal ◽  
British Museum ◽  
Museum Collection ◽  
X Ray ◽  
Fluorine Determination

It has recently been shown by W. Nieuwenkamp that matlockite is identical in chemical composition and crystal-structure with artificial lead fluochloride PbFC1. His conclusion is based upon powder photographs of the two substances and a fluorine determination of a specimen of matlockite from Matlock, Derbyshire. The present work was undertaken primarily to check Nieuwenkamp's interesting results. Access to an exceptionally fine suite of matlockite specimens in the British Museum collection made possible single crystal X-ray measurements, accurate optical determinations, and a new chemical analysis.

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

scholarly journals Magnetically Oriented Powder Crystal to Indexing and Structure Determination

2014 ◽  
Vol 70 (a1) ◽  
pp. C1560-C1560
Author(s):  
Fumiko Kimura ◽  
Wataru Oshima ◽  
Hiroko Matsumoto ◽  
Hidehiro Uekusa ◽  
Kazuaki Aburaya ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Crystal Lattice ◽  
Powder Diffraction ◽  
Diffraction Method ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal Lattice Parameters

In pharmaceutical sciences, the crystal structure is of primary importance because it influences drug efficacy. Due to difficulties of growing a large single crystal suitable for the single crystal X-ray diffraction analysis, powder diffraction method is widely used. In powder method, two-dimensional diffraction information is projected onto one dimension, which impairs the accuracy of the resulting crystal structure. To overcome this problem, we recently proposed a novel method of fabricating a magnetically oriented microcrystal array (MOMA), a composite in which microcrystals are aligned three-dimensionally in a polymer matrix. The X-ray diffraction of the MOMA is equivalent to that of the corresponding large single crystal, enabling the determination of the crystal lattice parameters and crystal structure of the embedded microcrytals.[1-3] Because we make use of the diamagnetic anisotropy of crystal, those crystals that exhibit small magnetic anisotropy do not take sufficient three-dimensional alignment. However, even for these crystals that only align uniaxially, the determination of the crystal lattice parameters can be easily made compared with the determination by powder diffraction pattern. Once these parameters are determined, crystal structure can be determined by X-ray powder diffraction method. In this paper, we demonstrate possibility of the MOMA method to assist the structure analysis through X-ray powder and single crystal diffraction methods. We applied the MOMA method to various microcrystalline powders including L-alanine, 1,3,5-triphenyl benzene, and cellobiose. The obtained MOMAs exhibited well-resolved diffraction spots, and we succeeded in determination of the crystal lattice parameters and crystal structure analysis.

scholarly journals Rubidium tetrafluoridobromate(III): redetermination of the crystal structure from single-crystal X-ray diffraction data

IUCrData ◽  
2019 ◽  
Vol 4 (11) ◽  
Author(s):  
Artem V. Malin ◽  
Sergei I. Ivlev ◽  
Roman V. Ostvald ◽  
Florian Kraus
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Single Crystals ◽  
Diffraction Data ◽  
Structure Type ◽  
X Ray Diffraction ◽  
X Ray ◽  
Square Planar ◽  
Atomic Coordinates

Single crystals of rubidium tetrafluoridobromate(III), RbBrF4, were grown by melting and recrystallizing RbBrF4 from its melt. This is the first determination of the crystal structure of RbBrF4 using single-crystal X-ray diffraction data. We confirmed that the structure contains square-planar [BrF4]− anions and rubidium cations that are coordinated by F atoms in a square-antiprismatic manner. The compound crystallizes in the KBrF4 structure type. Atomic coordinates and bond lengths and angles were determined with higher precision than in a previous report based on powder X-ray diffraction data [Ivlev et al. (2015). Z. Anorg. Allg. Chem. 641, 2593–2598].

An X-ray study of the crystal-structure of antigorite (With Plate V)

1945 ◽  
Vol 27 (188) ◽  
pp. 65-74 ◽  
Author(s):  
Endel Aruja
Keyword(s):  
Crystal Structure ◽  
Chemical Composition ◽  
Line Broadening ◽  
X Ray ◽  
Complete Determination

Antigorite is a lamellar variety of serpentine, and is supposed to be a dimorphous form of chrysotile, which is finely fibrous. Its chemical composition is approximately H4Mg3Si2O9, which is taken as the basis of calculations here.This study was undertaken primarily because it was hoped that knowledge of the structure of antigorite would throw some light on that of chrysotile. Certain similarities between the two structures have been established, namely in the c(7·3kX or 14·6kX), and b(9·2kX) directions. There are two main differences, however. Firstly, imperfections which cause line broadening in the X-ray pattern of chrysotile, are absent in antigorite (apart from certain ‘streaks’). Secondly, the a(43·4kX) axis of antigorite is approximately eight times longer than the corresponding axis in chrysotile. A complete determination of the structure has not been achieved, but the X-ray pattern has been described, and some suggestions made as to the explanation of the peculiarities observed. A further study of the outstanding questions is in progress.

The Constituents of Marine Sponges. V. The Isolation From Chelonaplysilla violacea (Dendroceratida) of Aplyviolene and Other Diterpenes, and the Determination of the Crystal Structure of Aplyviolene

1990 ◽  
Vol 43 (11) ◽  
pp. 1861 ◽  
Author(s):  
TW Hambley ◽  
A Poiner ◽  
WC Taylor
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Marine Sponge ◽  
Marine Sponges ◽  
Spectroscopic Methods ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Deep Violet

From the deep violet, encrusting marine sponge Chelonaplysilla violacea, two rearranged spongian diterpenes, aplyviolene, (1R*,1′S*,3?aR*,5R*,6R*,8R*,8′aS*)-3-oxo-8-(1′,4′,4′-trimethyl-8′-methylenedecahydroazulen-1′-yl)-2,7-dioxabicyclo[3.2.1]oct-6-yl acetate (1), the acetoxy derivative, aplyviolacene (2), (5R*,8S*,9S*,10R*,13S*,14R* ,15S*,16R*)-spongian-15,16-diyl diacetate (3) and (5R*,8S*,9S*,10R*,13S*,14R*)-spongian-16-one (4) were isolated. The structures were determined by spectroscopic methods, and the structure of aplyviolene was confirmed by a single-crystal X-ray determination. The crystal structure was refined to a residual of 0.036 for 1125 independent observed reflections. The crystals were orthorhombic, space group P212121 with a 8.098(1), b 11.628(1), c 21.774(3)Ǻ.

Structure of Sr-Zr-bearing perrierite-(Ce) from the Burpala Massif, Russia

2014 ◽  
Vol 78 (7) ◽  
pp. 1647-1659 ◽  
Author(s):  
Marcin Stachowicz ◽  
Bogusław Bagiński ◽  
Ray Macdonald ◽  
Pavel M. Kartashov ◽  
Artur OzięBło ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Chemical Composition ◽  
Single Crystal ◽  
Space Group ◽  
X Ray ◽  
Ccd Detector ◽  
Unique Site

AbstractSr- and Zr-bearing perrierite-(Ce) occurring in aegirinized syenite pegmatites of the Burpala massif, Russia, is compositionally intermediate between perrierite-(Ce) and hezuolinite and occupies a compositional gap in minerals of the chevkinite group. Its crystal structure has been determined using a single-crystal diffractometer fitted with a CCD detector and MoKα X-ray radiation. The mineral is monoclinic; a = 13.815(1), b = 5.668(1), c = 11.842(1) Å , β = 113.843(3)º, V = 848.18(4) Å3, space group C2/m, Z = 2. The crystal structure was refined with the occupancies [(Ce1.2La1.0Nd0.15) (Sr1.0Ca0.5Na0.15)]4(Zr0.5Fe0.3Mn0.2)(Ti1.3Fe0.7)2Ti2(Si2O7)2O8 on the basis of chemical composition although the allocation of cations to particular sites was performed on the basis of the number of refined electrons in each unique site. The dominance of Zr in the B site links the Burpala perrierite-(Ce) to more Sr-Zr-rich members of the chevkinite group, such as hezuolinite and rengeite. As in all of the perrierite members, there is a distortion of the D site octahedra, which is interpreted as due to the packing of the REE ions.

Kristallzucht und Strukturaufklärung von K2[Pt(CN)4Cl2], K2[Pt(CN)4Br2], K2[Pt(CN)4I2] und K2[Pt(CN)4Cl2] · 2H2O/ Crystal Growth and Crystal Structure Determination of K2[Pt(CN)4Cl2], K2[Pt(CN)4Br2], K2[Pt(CN)4I2] and K2[Pt(CN)4]Cl2] · 2H2O

2004 ◽  
Vol 59 (5) ◽  
pp. 567-572 ◽  
Author(s):  
Claus Mühle ◽  
Andrey Karpov ◽  
Jürgen Nuss ◽  
Martin Jansen
Keyword(s):  
Crystal Structure ◽  
Infrared Spectroscopy ◽  
Crystal Growth ◽  
Single Crystal ◽  
Structure Determination ◽  
Spectroscopy Data ◽  
Crystal Data ◽  
X Ray ◽  
Raman And Infrared Spectroscopy

Abstract Crystals of K2Pt(CN)4Br2, K2Pt(CN)4I2 and K2Pt(CN)4Cl2 ·2H2O were grown, and their crystal structures have been determined from single crystal data. The structure of K2Pt(CN)4Cl2 has been determined and refined from X-ray powder data. All compounds crystallize monoclinicly (P21/c; Z = 2), and K2Pt(CN)4X2 with X = Cl, Br, I are isostructural. K2Pt(CN)4Cl2: a = 708.48(2); b = 903.28(3); c = 853.13(3) pm; β = 106.370(2)°; Rp = 0.064 (N(hkl) = 423). K2Pt(CN)4Br2: a = 716.0(1); b = 899.1(1); c = 867.9(1) pm; β = 106.85(1)°; R(F)N′ = 0.026 (N’(hkl) = 3757). K2Pt(CN)4I2: a = 724.8(1); b = 914.5(1); c = 892.1(1) pm; β = 107.56(1)°; R(F)N′ = 0.025 (N’(hkl) = 2197). K2Pt(CN)4Cl2 ·2H2O: a = 763.76(4); b = 1143.05(6); c = 789.06(4) pm; β = 105.18(1)°; R(F)N′ = 0.021 (N’(hkl) = 2281). Raman and infrared spectroscopy data are reported.

Crystal structure determination of Ag2Ga by single crystal X-ray diffraction

1998 ◽  
Vol 213 (12) ◽  
Author(s):  
A. E. Gunnæs ◽  
A. Olsen ◽  
P. T. Zagierski ◽  
B. Klewe ◽  
O. B. Karlsen ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Structure Determination ◽  
Crystal Structure Determination ◽  
X Ray Diffraction ◽  
X Ray

AbstractThe crystal structure of

The Choice of Chemical Composition and Raw Materials for the Production of Basalt Wool with the Defined Characteristics

2018 ◽  
Vol 284 ◽  
pp. 1018-1023
Author(s):  
A.V. Khandoshka ◽  
Svetlana G. Vlasova
Keyword(s):  
Surface Tension ◽  
Chemical Composition ◽  
Chemical Analysis ◽  
Thermal Insulation ◽  
Raw Materials ◽  
Mineral Wool ◽  
Chemical Compositions ◽  
Insulation Material ◽  
X Ray

The composition of mineral wool was selected for the research, based on the chemical composition of the raw materials, the determination of the acidity module to obtain the thermal insulation material with the best characteristics and the lowest cost of the production of basalt mineral wool. The paper deals with compositions of raw materials and selection chemical compositions of charges for production of basalt mineral wool, and the experiments of welded samples were made and tested for viscosity, surface tension, chemical analysis and x-ray analysis.

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