The characterization of serpentine minerals by X-ray diffraction

Author(s):  
E. J. W. Whittaker ◽  
J. Zussman

SummaryX-ray diffraction data on serpentine minerals are discussed. There arc three structural varieties of chrysotile: ortho-chrysotile, clino-chrysotile, and para-chrysotile. Methods are described for the estimation of the proportions of the first two of these in mixed specimens, and their distribution in nature is reviewed. The variations observed in powder photographs of serpentine minerals are interpreted in accordance with this classification. The criteria proposed by Selfridge for distinguishing between chrysotile and antigorite are shown to be unreliable, but valid criteria are presented. The powder photographs also reveal the existence of a third serpentine mineral, distinct from chrysotile and antigorite, for which the name lizardite is proposed. Four samples of bastite are shown to consist of chrysotile or lizardite rather than antigorite. All the serpentine minerals examined consist either of antigorite or of one or more of the group comprising lizardite and the chrysotile varieties.

Chemistry ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. 591-599
Author(s):  
Brock A. Stenfors ◽  
Richard J. Staples ◽  
Shannon M. Biros ◽  
Felix N. Ngassa

Treatment of 2,4-dinitrophenol with sulfonyl chlorides in the presence of pyridine results in the formation of undesired pyridinium salts. In non-aqueous environments, the formation of the insoluble pyridinium salt greatly affects the formation of the desired product. A facile method of producing the desired sulfonate involves the use of an aqueous base with a water-miscible solvent. Herein, we present the optimization of methods for the formation of sulfonates and its application in the production of desired x-substituted 2,4-dinitrophenyl-4′-phenylbenzenesulfonates. This strategy is environmentally benign and supports a wide range of starting materials. Additionally, the intermolecular interactions of these sulfonate compounds were investigated using single-crystal x-ray diffraction data.


2013 ◽  
Vol 717 ◽  
pp. 133-138
Author(s):  
A. Awad Allah ◽  
M. Elhadi ◽  
O.A. Yassien

The crystal structure of both samples has been solved by powder X-ray diffraction, data in the tetragonal space group I4/m (a= b= 5.55182 Å, c =7.86955 A0) for SrLaFeNi0.5W0.5O6sample and (a=b= 5.49129Å, c= 7.82233Å) for CaLaFeNi0.5W0.5O6 sample, and shows an almost perfect ordering between Ni2+ and W5+ cations at the B-site of the perovskite structure. The FTIR spectrometer used of the powders showed that the spectra of both are very similar, showing two strong and well-defined absorption bands, typical of perovskite materials.


2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
Guido Ennas ◽  
Maria F. Casula ◽  
Sergio Marras ◽  
Gabriele Navarra ◽  
Alessandra Scano ◽  
...  

A nanocomposite with an FeOOH/SiO2ratio equal to 17.7 wt% and the pertinent matrix, obtained by etching away the nanoparticles through reaction with hydrochloric acid, were investigated by XRD, TGA-DTA, heliostereopicnometry, BET, and TEM techniques. The study shows the presence in the nanocomposite of ferrihydrite nanoparticles phase with average dimensions around 4 nm. The FeOOH nanoparticles structure was analyzed by synchrotron X-ray diffraction data using the distribution difference curve method. The porous structure of the matrix resulting by etching away the nanoparticles differs significantly from that of a pureSiO2sample obtained by hydrolysis of TEOS under the same operative conditions followed in the nanocomposite preparation.


2017 ◽  
Vol 72 (2) ◽  
pp. 153-158 ◽  
Author(s):  
Sebastian Bräuchle ◽  
Hubert Huppertz

AbstractLi3Y(BO3)2 was prepared by high-temperature solid state synthesis at 900°C in a platinum crucible from lithium carbonate, boric acid, and yttrium(III) oxide. The compound crystallizes monoclinically in the space group P21/c (no. 14) (Z=4) isotypically to Li3Gd(BO3)2. The structure was refined from single-crystal X-ray diffraction data: a=8.616(3), b=6.416(3), c=10.014(2) Å, β=116.6(2)°, V=494.9(3) Å3, R1=0.0211, and wR2=0.0378 for all data. The crystal structure of Li3Y(BO3)2 consists of [Y2O14] dinuclear units, which are interconnected to each other by planar B(1)O3 groups and LiO4 tetrahedra via common edges and corners along the a axis.


1997 ◽  
Vol 53 (3) ◽  
pp. 504-512 ◽  
Author(s):  
A. Martin ◽  
A. A. Pinkerton ◽  
R. D. Gilardi ◽  
J. C. Bottaro

Three biguanidinium salts of the energetic dinitramide anion have been prepared and structurally characterized from room-temperature X-ray diffraction data. Biguanidinium mono-dinitramide, (BIGH)(DN), triclinic, P\overline 1, a = 4.3686 (4), b = 9.404 (2), c = 10.742 (1) Å, \alpha = 83.54 (1), \beta = 80.386 (9), \gamma = 79.93 (1)°, V = 426.8 (1) Å3, Z = 2, D x = 1.62 g cm−3. Biguanidinium bis-dinitramide, (BIGH2)(DN)2, monoclinic, C2/c, a = 11.892 (2), b = 8.131 (1), c = 13.038 (2) Å, \beta = 115.79 (1)°, V = 1135.1 (3) Å3, Z = 4, D x = 1.84 g cm−3. Biguanidinium bis-dinitramide monohydrate, (BIGH2)(DN)2.H2O, orthorhombic, P212121, a = 6.4201 (6), b = 13.408 (1), c = 14.584 (2) Å, V = 1255.4 (4) Å3, Z = 4, D x = 1.76 g cm−3. All three structures are characterized by extensive hydrogen bonding. Both the mono- and diprotontated cations consist of two planar halves twisted with respect to each other. The dinitramide anion has a surprisingly variable and asymmetric structure. The two halves of the anion are twisted with respect to each other; however, the twist varies from 5.1 to 28.9°. In addition, the two ends of the anion have significantly different geometries, e.g. the `equivalent' N—N bond lengths differ by up to 0.045 Å.


2016 ◽  
Vol 71 (12) ◽  
pp. 1225-1232
Author(s):  
Sebastian Bräuchle ◽  
Clivia Hejny ◽  
Hubert Huppertz

AbstractBaSr2Ge3O9 was prepared by high-temperature solid-state synthesis at 1100°C in a platinum crucible from barium carbonate, strontium carbonate, and germanium(IV) oxide. The compound crystallizes in the triclinic space group P1̅ (no. 2) isotypically to walstromite BaCa2Si3O9. The structure was refined from single-crystal X-ray diffraction data: a=7.104(5), b=10.060(7), c=7.099(5) Å, α=83.0(2), β=77.0(2), γ=70.2(2)°, V=464.3(6) Å3, R1=0.0230, and wR2=0.0602 for all data. BaSr2Ge3O9 is characterized by three-membered rings of germanate tetrahedra. There are three crystallographically different Ge sites (Ge1, Ge2, and Ge3) in each [Ge3O9]6− ring. The rings occur in layers with the apices of alternating rings pointing in opposite directions. The Sr2+ and Ba2+ ions are located in between. The Sr1 cation is eight-fold coordinated, while Sr2 is octahedrally surrounded by oxide anions, and the Ba cation again eight-fold coordinated.


2002 ◽  
Vol 57 (3) ◽  
pp. 360-362 ◽  
Author(s):  
Yetta Porter ◽  
P. Shiv Halasyamani

AbstractThe first labortory synthesis and characterization of the mineral Nadorite, PbSbO2Cl, is reported. The material was synthesized by combining PbCl2, PbO and Sb2O3. Powder X-ray diffraction data on the polycrystalline product is consistent with the previously reported crystal structure on the mineral. Infrared and thermogravimetric data are also present.


2017 ◽  
Vol 72 (12) ◽  
pp. 959-965 ◽  
Author(s):  
Sebastian Bräuchle ◽  
Markus Seibald ◽  
Hubert Huppertz

AbstractLi3K3Eu7(BO3)9 was prepared by high-temperature solid state synthesis at 900°C in a platinum crucible from lithium carbonate, potassium carbonate, boric acid, and europium(III) oxide. The title compound crystallizes in the orthorhombic space group Pca21 (no. 29) (Z=4). The structure was refined from single-crystal X-ray diffraction data: a=21.126(2), b=6.502(2), c=17.619(2) Å, V=2420.1(2) Å3, R1=0.0183 and wR2=0.0412 for all data. The crystal structure of Li3K3Eu7(BO3)9 is isotypic to Li3K3Y7(BO3)9 featuring isolated BO3 units and LiO6 octahedra forming [Li3B4O21] units in the ac plane, which are linked by additional BO3 units. The K+ and Eu3+ cations are arranged in the cavities of the structure.


2009 ◽  
Vol 24 (1) ◽  
pp. 44-47 ◽  
Author(s):  
S. G. Antonio ◽  
C. O. Paiva-Santos ◽  
P. P. Corbi ◽  
A. C. Massabni ◽  
F. C. Andrade

Powder X-ray diffraction studies of a lithium salt of thiazolidine-4-carboxylic acid (Li-TC4) of composition LiC4H6NSO2 are presented in this paper. Analysis of the synchrotron powder X-ray diffraction data showed that the complex has an orthorhombic symmetry with space group P212121. Unit cell parameters after the refinement using the Pawley method are: a=19.4931(3) Å, b=4.947 77(6) Å, c=6.201 64(8) Å, and V=598.051 Å3.


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