Single-crystal X-ray diffraction, EMPA, FTIR and X-ray photoelectron spectroscopy study of narsarsukite from Murun Massif, Russia

2017 ◽  
Vol 81 (2) ◽  
pp. 339-354 ◽  
Author(s):  
E. Schingaro ◽  
E. Mesto ◽  
M. Lacalamita ◽  
F. Scordari ◽  
E. Kaneva ◽  
...  
Keyword(s):  
Single Crystal ◽  
Photoelectron Spectroscopy ◽  
Chemical Study ◽  
Structural Disorder ◽  
Crystal Chemical ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Alkaline Massif

AbstractA crystal chemical study of narsarsukite from the Murun alkaline massif, Russia has been carried out combining single-crystal X-ray diffraction, electron microprobe analyses, micro-Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The narsarsukite single crystals are tetragonal (space group I4/m) with unit-cell parameters: 10.7140(1) ≤ a ≤ 10.7183(2) Å and 7.9478(1) ≤ c ≤ 7.9511(1) Å. The XPS analysis showed that Fe occurs in the mineral as Fe3+, whereas the FTIR spectrum showed that the sample studied is anhydrous. The average crystal chemical formula of the Murun narsarsukite is: Na2.04K0.01(V0.015+Ti0.74Zr0.01Al0.01Fe0.223+Mg0.01)1.00Si4.00(O10.74F0.23OH0.03)11.00. Structural disorder at octahedral and interstitial sites was modelled and also discussed in consideration of the main substitutional mechanism Ti4+ + O2– ↔ Fe3+ + (F–, OH–) active in the structure of the mineral.

Refinement of the crystal structure of sieleckiite and revision of its symmetry

2017 ◽  
Vol 81 (4) ◽  
pp. 917-922
Author(s):  
Peter Elliott
Keyword(s):  
Crystal Structure ◽  
Synchrotron Radiation ◽  
Single Crystal ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Aluminium Phosphate ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Phosphate Mineral

AbstractThe crystal structure of the copper aluminium phosphate mineral sieleckiite, Cu3Al4(PO4)2 (OH)12·2H2O, from the Mt Oxide copper mine, Queensland, Australia was solved from single-crystal X-ray diffraction data utilizing synchrotron radiation. Sieleckiite has monoclinic rather than triclinic symmetry as previously reported and is space group C2/m with unit-cell parameters a = 11.711(2), b = 6.9233(14), c = 9.828(2) Å, β = 92.88(3)°, V = 795.8(3) Å3and Z = 2. The crystal structure, which has been refined to R1 = 0.0456 on the basis of 1186 unique reflections with Fo > 4σF, is a framework of corner-, edge- and face- sharing Cu and Al octahedra and PO4 tetrahedra.

X-ray Diffraction Study of the Crystal Structure of the Tl Ternary Chalcogenides Tl2x In2(1−x)Se2, x = 0.2, 0.3,...0.9

1998 ◽  
Vol 54 (4) ◽  
pp. 358-364 ◽  
Author(s):  
K. G. Hatzisymeon ◽  
S. C. Kokkou ◽  
A. N. Anagnostopoulos ◽  
P. I. Rentzeperis
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Rietveld Method ◽  
Direct Methods ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Volume Decrease

A series of thallium ternary chalcogenides with the composition Tl2x In2(1−x)Se2, x = 0.2, 0.3,...0.9, have been studied by X-ray powder and, for some of them, single-crystal diffraction. They are tetragonal, space group I4/mcm, Z = 4, and isostructural with the binary semiconductor TlSe. Their crystal structures have been solved by direct methods and refined by the Rietveld method to a precision which is satisfactorily comparable to single-crystal results. As x is changed from x = 0.2 to x = 0.9 the unit-cell parameters and volume decrease or increase following Kurnakov's law, which is valid for solid solutions. Refined positional parameters of Se, In—Se and Tl—Se bond lengths vary with x also according to the same law. The distribution of In and Tl cations in 4(a) and 4(b) sites depends on the stoichiometry x and the crystals are composed of [In3+Se2]_{\infty}^- chains along the c axis in which InSe4 tetrahedra share edges; the chains are interconnected with Tl+(In+) ions.

scholarly journals Na-dominant (at the M2 site) eudialyte analogue: crystal structure and indicatory significance

2020 ◽  
Vol 9 ◽  
pp. 19-25
Author(s):  
R. K. Rastsvetaeva ◽  
◽  
N. V. Chukanov ◽  
Ch. Schäfer ◽  
Keyword(s):  
Crystal Structure ◽  
Electron Probe ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Eudialyte Group ◽  
X Ray ◽  
Cell Parameters ◽  
Atomic Displacements ◽  
Alkaline Massif

Minerals of the eudialyte group from ultra-agpaitic associations are often characterized by high contents (up to the dominance) of sodium at the M2 site, which is populated with iron in eudialyte. The features of blocky isomorphism with the replacement of IVFe2+ by IVNa and VNa at the M2 micro-region are discussed. Using the methods of electron probe microanalysis, X-ray diffraction and IR spectroscopy, a potentially new mineral, M2Na-dominant analogue of eudialyte from the Ilimaussaq alkaline massif (Greenland), was investigated. Its crystal structure was refined to R = 5.6 % in the anisotropic approximation of atomic displacements using 1095 independent reflections with F > 3(F). The unit-cell parameters are: a = 14.208(1), c = 30.438(1) Å, V = 5321(1) Å3; the space group is R-3m. The idealized formula of the mineral is (Z = 3): (Na,H3O)15Ca6Zr3[Na2Fe][Si26O72](OH)2Cl∙2H2O.

Molecular and crystal structure of a copper(II) complex of sildenafil

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Akhmatkhodja N. Yunuskhodjayev ◽  
Shokhista F. Iskandarova ◽  
Vahobjon Kh. Sabirov
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Piperazine Ring ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

Abstract The crystal structure of a copper(II) complex of protonated sildenafil, CuCl3C22H31N6O4S⋅2H2O was studied by single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P21/n with the unit cell parameters a = 15.4292(2), b = 9.06735(12), c = 21.1752(2) Å, V = 2945.48(7) Å3, Z = 4. The Cu atom is coordinated by the sildenafil ligand via the N2 atom of the pyrazolopyrimidine ring and by three chloride anions. Sildenafil is protonated at the methylated N6 atom of the piperazine ring and it is cation ligand with a 1+ charge.

Reactions between Co(II), 1,2-bis(diphenylphosphino)ethane, and NaBH3CN in the presence and absence of CO. The crystal structure of bis(cyanotrihydroborato)tetrakis(N,N-dimethylformamide)cobalt(II)

1988 ◽  
Vol 66 (7) ◽  
pp. 1770-1775 ◽  
Author(s):  
David J. Elliot ◽  
Sanna Haukilahti ◽  
David G. Holah ◽  
Alan N. Hughes ◽  
Stanislaw Maciaszek ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
R Factor

Reactions between Co(II), Diphos, and NaBH3CN lead to Co(BH3CN)2(Diphos)2, 1, or [Co(BH3CN)(Diphos)2]X, 2 (X = ClO4 or BPh4), and, in certain solvents, 2 reacts to produce [Co(CN)(Diphos)2](ClO4). Compound 1 can be reversibly converted to Co(BH3CN)2(DMF)4, 4, via Co(BH3CN)2(Diphos)(DMF). In addition, 1 reacts with CO to form the Co(I) and Co(III) compounds [Co(Diphos)2](CO)]X and [Co(Diphos)2(CN)2]X (X = BH3CN or BPh4). Single crystal X-ray diffraction studies of 4 show that the compound crystallizes in the triclinic space group [Formula: see text], with unit cell parameters a = 7.572(6), b = 9.695(6), c = 9.395(6) Å, α = 81.06(4), β = 68.46(5), γ = 68.19(5)°, V = 595.5 Å3, Z = 1, and dcalcd = 1.202 g cm−3. The structure converged to a conventional R factor of 0.040 for 2841 observations and showed an octahedral arrangement of four O atoms from DMF molecules and two trans N-bound BH3CN groups around the Co(II) center.

X-ray diffraction data of C16H14O4Ru2M (M=Ge,Si)

2002 ◽  
Vol 17 (1) ◽  
pp. 44-47
Author(s):  
Yu PuLan ◽  
Ding Shuang ◽  
Qiao YuanYuan ◽  
Yao XinKan ◽  
Liu Chong ◽  
...  
Keyword(s):  
Single Crystal ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Monoclinic Cell ◽  
Good Agreement

Two compounds have been studied by means of powder diffraction and their unit cell parameters are reported. The monoclinic cell parameters for dimethylgermanyl-bridged bis cyclopentadienyl tetracarbonyl diruthenium are a=11.03(2) Å, b=13.65(2) Å, c=11.609(2) Å, β=105.81(1)°, Z=4, space group P21/n (No. 14), Dx=2.135 mg/m3. The monoclinic cell parameters for λ-dimethylsilyl-dicyclopentadienyl-π, π′-tetracarbonyl diruthenium, are a=11.113(3) Å, b=13.60(1) Å, c=11.674(7) Å, and β=106.00(3)°, Z=4, space group P21/n (No. 14), and Dx=1.946 mg/m3. The cells found for the two compounds are in good agreement with those obtained from single crystal X-ray diffractometry.

scholarly journals Structural Trends and Solid-Solutions Based on the Crystal Chemistry of Two Hausmannite (Mn3O4) Samples from the Kalahari Manganese Field

Minerals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 343 ◽  
Author(s):  
Sytle M. Antao ◽  
Laura A. Cruickshank ◽  
Kaveer S. Hazrah
Keyword(s):  
Single Crystal ◽  
Crystal Chemistry ◽  
Structure Refinement ◽  
Site Occupancy ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Jahn Teller

The crystal chemistry of two hausmannite samples from the Kalahari manganese field (KMF), South Africa, was studied using electron-probe microanalysis (EPMA), single-crystal X-ray diffraction (SCXRD) for sample-a, and high-resolution powder X-ray diffraction (HRPXRD) for sample-b, and a synthetic Mn3O4 (97% purity) sample-c as a reference point. Hausmannite samples from the KMF were reported to be either magnetic or non-magnetic with a general formula AB2O4. The EPMA composition for sample-a is [Mn2+0.88Mg2+0.11Fe2+0.01]Σ1.00Mn3+2.00O4 compared to Mn2+Mn3+2O4 obtained by refinement. The single-crystal structure refinement in the tetragonal space group I41/amd gave R1 = 0.0215 for 669 independently observed reflections. The unit-cell parameters are a = b = 5.7556(6), c = 9.443(1) Å, and V = 312.80(7) Å3. The Jahn–Teller elongated Mn3+O6 octahedron of the M site consists of M–O × 4 = 1.9272(5), M–O × 2 = 2.2843(7), and an average <M–O>[6] = 2.0462(2) Å, whereas the Mn2+O4 tetrahedron of the T site has T–O × 4 = 2.0367(8) Å. The site occupancy factors (sof) are M(sof) = 1.0 Mn (fixed, thereafter) and T(sof) = 1.0008(2) Mn. The EPMA composition for sample-b is [Mn0.99Mg0.01](Mn1.52Fe0.48)O4. The Rietveld refinement gave R (F2) = 0.0368. The unit-cell parameters are a = b = 5.78144(1), c = 9.38346(3) Å, and V = 313.642(1) Å3. The octahedron has M–O × 4 = 1.9364(3), M–O × 2 = 2.2595(6), and average <M–O>[6] = 2.0441(2) Å, whereas T–O × 4 = 2.0438(5) Å. The refinement gave T(sof) = 0.820(9) Mn2+ + 0.180(9) Fe2+ and M(sof) = 0.940(5) Mn3+ + 0.060(5) Fe3+. Samples-a and -b are normal spinels with different amounts of substitutions at the M and T sites. The Jahn–Teller elongation, Δ(M–O), is smaller in sample-b because atom substitutions relieve strain compared to pure Mn3O4.

scholarly journals LCP crystallization and X-ray diffraction analysis of VcmN, a MATE transporter fromVibrio cholerae

2016 ◽  
Vol 72 (7) ◽  
pp. 552-557 ◽  
Author(s):  
Tsukasa Kusakizako ◽  
Yoshiki Tanaka ◽  
Christopher J. Hipolito ◽  
Teruo Kuroda ◽  
Ryuichiro Ishitani ◽  
...  
Keyword(s):  
Single Crystal ◽  
Diffraction Data ◽  
Unit Cell ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Mate Transporter

Multidrug and toxic compound extrusion (MATE) transporters, one of the multidrug exporter families, efflux xenobiotics towards the extracellular side of the membrane. Since MATE transporters expressed in bacterial pathogens contribute to multidrug resistance, they are important therapeutic targets. Here, a MATE-transporter homologue fromVibrio cholerae, VcmN, was overexpressed inEscherichia coli, purified and crystallized in lipidic cubic phase (LCP). X-ray diffraction data were collected to 2.5 Å resolution from a single crystal obtained in a sandwich plate. The crystal belonged to space groupP212121, with unit-cell parametersa= 52.3,b= 93.7,c= 100.2 Å. As a result of further LCP crystallization trials, crystals of larger size were obtained using sitting-drop plates. X-ray diffraction data were collected to 2.2 Å resolution from a single crystal obtained in a sitting-drop plate. The crystal belonged to space groupP212121, with unit-cell parametersa= 61.9,b= 91.8,c= 100.9 Å. The present work provides valuable insights into the atomic resolution structure determination of membrane transporters.

scholarly journals Crystal structures and comparisons of huntite aluminum borates REAl3(BO3)4 (RE = Tb, Dy and Ho)

2020 ◽  
Vol 76 (3) ◽  
pp. 339-343 ◽  
Author(s):  
Saehwa Chong ◽  
Brian J. Riley ◽  
Zayne J. Nelson ◽  
Samuel N. Perry
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Structural Parameters ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Slow Cooling ◽  
Spontaneous Crystallization ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

Three huntite-type aluminoborates of stoichiometry REAl3(BO3)4 (RE = Tb, Dy and Ho), namely, terbium/dysprosium/holmium trialuminium tetrakis(borate), were synthesized by slow cooling within a K2Mo3O10 flux with spontaneous crystallization. The crystal structures were determined using single-crystal X-ray diffraction (SC-XRD) data. The synthesized borates are isostructural to the huntite [CaMg3(CO3)4] structure and crystallized within the trigonal R32 space group. The structural parameters were compared to literature data of other huntite REAl3(BO3)4 crystals within the R32 space group. All three borates fit well into the trends calculated from the literature data. The unit-cell parameters and volumes increase linearly with larger RE cations whereas the densities decrease. All of the crystals studied were refined as inversion twins.

Ognitite, NiBiTe, a new mineral species, and Co-rich maucherite from the Ognit ultramafic complex, Eastern Sayans, Russia

2019 ◽  
Vol 83 (5) ◽  
pp. 695-703 ◽  
Author(s):  
Andrei Y. Barkov ◽  
Luca Bindi ◽  
Nobumichi Tamura ◽  
Gennadiy I. Shvedov ◽  
Björn Winkler ◽  
...  
Keyword(s):  
Single Crystal ◽  
Diffraction Data ◽  
Unit Cell ◽  
Synthetic Analogue ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
New Mineral Species ◽  
Ultramafic Complex

AbstractWe describe the new species ognitite, NiBiTe, and a Co-rich variety of maucherite, hitherto unreported; both were discovered in the Ognit ultramafic complex of Neoproterozoic age in Eastern Sayans, Russia. The mean composition of ognitite (n = 7) is: Ni 17.05, Fe 0.07, Cu 0.14, Pd 0.14, Te 32.53, Bi 49.64, total 99.57 wt.%, corresponding to: (Ni1.11Cu0.008Fe0.005Pd0.005)Σ1.13Bi0.90Te0.97 (Σ atoms = 3 apfu). Ognitite is trigonal, space group P3m1 [R1 = 0.0276 for 81 reflections with Fo > 4σ(Fo)]. The unit-cell parameters derived from the single-crystal X-ray diffraction data are: a = 3.928(1) Å, c = 5.385(1) Å and V = 71.95(4) Å3, with Z = 1. The c:a ratio is 1.37. The powder X-ray diffraction data obtained on the same fragment used for the single-crystal study are: a = 3.9332(4) Å, c = 5.3920(6) Å and V = 72.24(1) Å3. Ognitite exhibits the brucite-type structure with edge-sharing NiTe3Bi3 octahedra forming sheets parallel to (0001). It is related to melonite, but is distinct compositionally by the extreme Bi-enrichment (melonite and its synthetic analogue contain <0.4 Bi apfu), and structurally as Bi and Te are ordered at two distinct sites, leading to the loss of the centre of symmetry in ognitite.At more than 9 wt.% Co, or ~2 apfu Co, the core of Co-rich maucherite [(Ni,Co)11As8] in a zoned crystal, which is surrounded by Co-depleted orcelite, far surpasses the norm (≤1 and up to 3.9 wt.% Co). The unit-cell parameters of the Co-rich maucherite are: a = 6.85(2) and c = 21.83(5) Å, which are based on results of synchrotron micro-Laue diffraction.The host rock consists of serpentine, clinochlore (Mg# 95–97) and skeletal chromite. We favour the metastable crystallisation of fluid-saturated globules of a sulfide–arsenide melt to explain the anomalous compositions of ore minerals at Ognit. These anomalies seem consistent with rapid cooling in a fluid-enriched system, possibly related to late-stage degassing of the magma, as reflected in a prominent metasomatic aureole at the contact with the enclosing gneissic rocks.

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