The crystal structures of the mixed-valence tellurium oxysalts tlapallite, (Ca,Pb)3CaCu6[Te4+3Te6+O12]2(Te4+O3)2(SO4)2·3H2O, and carlfriesite, CaTe4+2Te6+O8

2019 ◽  
Vol 83 (4) ◽  
pp. 539-549 ◽  
Author(s):  
Owen P. Missen ◽  
Anthony R. Kampf ◽  
Stuart J. Mills ◽  
Robert M. Housley ◽  
John Spratt ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Mixed Valence ◽  
Oxidation States ◽  
Structural Refinement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Naturally Occurring ◽  
The One ◽  
Micro Analysis ◽  
Secondary Bonding

ABSTRACTThe crystal structure of tlapallite has been determined using single-crystal X-ray diffraction and supported by electron probe micro-analysis, powder diffraction and Raman spectroscopy. Tlapallite is trigonal, space groupP321, witha= 9.1219(17) Å,c= 11.9320(9) Å andV= 859.8(3) Å3, and was refined toR1= 0.0296 for 786 reflections withI> 2σ(I). This study resulted from the discovery of well-crystallised tlapallite at the Wildcat prospect, Utah, USA. The chemical formula of tlapallite has been revised to (Ca,Pb)3CaCu6[Te4+3Te6+O12]2(Te4+O3)2(SO4)2·3H2O, or more simply (Ca,Pb)3CaCu6Te4+8Te6+2O30(SO4)2·3H2O, from H6(Ca,Pb)2(Cu,Zn)3(TeO3)4(TeO6)(SO4). The tlapallite structure consists of layers containing distorted Cu2+O6octahedra, Te6+O6octahedra and Te4+O4disphenoids (which together form the new mixed-valence phyllotellurate anion [Te4+3Te6+O12]12−), Te4+O3trigonal pyramids and CaO8polyhedra. SO4tetrahedra, Ca(H2O)3O6polyhedra and H2O groups fill the space between the layers. Tlapallite is only the second naturally occurring compound containing tellurium in both the 4+and 6+oxidation states with a known crystal structure, the other being carlfriesite, CaTe4+2Te6+O8. Carlfriesite is the predominant secondary tellurium mineral at the Wildcat prospect. We also present an updated structure for carlfriesite, which has been refined toR1= 0.0230 for 874 reflections withI> 2σ(I). This updated structural refinement improves upon the one reported previously by refining all atoms anisotropically and presenting models of bond valence and Te4+secondary bonding.

Crystal structure of 2,3-Dichloro-5,8-dihydroxynaphtho-1,4-quinone

1978 ◽  
Vol 31 (3) ◽  
pp. 555 ◽  
Author(s):  
GI Feutrill ◽  
CL Raston ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Benzene Ring ◽  
Title Compound ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
X Ray ◽  
The One ◽  
Least Squares Techniques

The crystal structure of the title compound has been determined at 295 K by single-crystal X-ray diffraction methods and refined by least- squares techniques to a residual of 0.049 for 1046 'observed' reflections. Crystals are monoclinic, P21/c, a 11.584(6), b 5.449(7), c 15.273(8) Ǻ, β 92.44(4)°, Z4. The pair of quinol hydrogen atoms are both located on the one benzene ring as the title indicates.

scholarly journals The crystal structure of parkinsonite, nominally Pb7MoO9Cl2: a naturally occurring Aurivillius phase

2010 ◽  
Vol 74 (2) ◽  
pp. 269-275 ◽  
Author(s):  
G. O. Lepore ◽  
M. D. Welch
Keyword(s):  
Crystal Structure ◽  
Electron Diffraction ◽  
X Ray Diffraction ◽  
Aurivillius Phase ◽  
X Ray ◽  
Cell Parameters ◽  
Naturally Occurring ◽  
Final Agreement ◽  
Fourfold Axis ◽  
Synthetic Crystal

AbstractThe crystal structure of the sheet oxychloride mineral parkinsonite, nominally Pb7MoO9Cl2, has been determined for synthetic and natural crystals of analysed compositions, (Pb7.28Mo0.72) O8.96Cl1.96 and (Pb7.23Mo0.40V0.37)O8.90Cl1.82, respectively. Parkinsonite is tetragonal, space group I4/mmm. Unit-cell parameters for synthetic and natural crystals are: asynthetic = 3.9773(4) Å, csynthetic = 22.718(4) Å, Vsynthetic = 359.38(5) Å3, and anatural = 3.9570(3) Å, cnatural = 22.634(5) Å, Vnatural = 354.40(5) Å3. Final agreement indices (R1, wR2) for refinements of the two crystals are 0.024, 0.067 (synthetic) and 0.036, 0.078 (natural). Although a superlattice has been identified by electron diffraction for crystals of both samples (Welch et al., 1996), only the substructure could be determined by X-ray diffraction. This X-ray invisibility of the superstructure has also been observed for the closely related sheet oxychlorides asisite and schwartzembergite, for both of which superstructure motifs have been identified by electron diffraction. The Pb(1) site of both parkinsonite crystals is fully occupied by Pb. Refinement of the Pb content of the Pb(2) site for the synthetic and natural crystals gives occupancies of 0.85(1) and 0.70(1) respectively, corresponding to 3.40 and 2.80 Pb(2) a.p.f.u. respectively. The substituent cation Mo (synthetic crystal) and [Mo+V] (natural crystal) was located at a distance of 0.5 Å from Pb(2), being displaced along the fourfold axis. The reduced occupancy of Pb(2) is due to substitution by Mo or [Mo+V]. No evidence for separate Mo and V sites in the substructure of natural parkinsonite was found. Refined occupancies of the Cl site are 0.84(4) and 0.91(5) for the synthetic and natural crystals, respectively, and are consistent with the 9:1 superstructure component identified by electron diffraction.

Highly Textured (111) Pt Substrates for Preferred Orientation Controlled AlN Films

2011 ◽  
Vol 675-677 ◽  
pp. 1259-1262 ◽  
Author(s):  
Takashi Harumoto ◽  
Shinji Muraishi ◽  
Ji Shi ◽  
Yoshio Nakamura
Keyword(s):  
Crystal Structure ◽  
Residual Stress ◽  
Preferred Orientation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tilting Angle ◽  
Diffraction Angle ◽  
The One

Preferred orientation of AlN films has been improved to c-axis using a highly (111) textured Pt layer. The highly textured (111) Pt layer is obtained by inserting an AlN layer between the Pt layer and substrate. Thus, Pt/AlN/substrate could be termed a substrate for preferred orientation controlled AlN films. X-ray diffraction (XRD) profiles reveal that the degree of preferred orientation of such highly (111) textured Pt layer surpasses the one originated from the crystal structure of Pt. The (2θ, ψ) intensify maps of diffracted X-ray collected as a function of the diffraction angle (2θ) and the tilting angle (ψ) exhibit that the films are perfectly (111) preferred orientated, however, they do not show in-plane texture. The (2θ, ψ) maps also demonstrate that a residual stress in films is subject to compressive.

Antofagastaite, Na2Ca(SO4)2·1.5H2O, a new mineral related to syngenite

2019 ◽  
Vol 83 (6) ◽  
pp. 781-790
Author(s):  
Igor V. Pekov ◽  
Vadim M. Kovrugin ◽  
Oleg I. Siidra ◽  
Nikita V. Chukanov ◽  
Dmitry I. Belakovskiy ◽  
...  
Keyword(s):  
Crystal Structure ◽  
New Mineral ◽  
Formula Unit ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Quartz Veins ◽  
Tolbachik Volcano ◽  
Mohs Hardness ◽  
The One

AbstractThe new mineral antofagastaite, ideally Na2Ca(SO4)2·1.5H2O, was found in the oxidation zone of sulfide–quartz veins at the abandoned Coronel Manuel Rodríguez mine, Mejillones, Antofagasta Province, Antofagasta Region, Chile. It is associated with sideronatrite, metasideronatrite, aubertite, gypsum, ferrinatrite, glauberite, amarillite and an unidentified Fe phosphate. Antofagastaite occurs as prismatic crystals up to 0.5 mm × 1 mm × 5 mm, elongated along [010], typically combined in open-work aggregates up to 1 cm across. Antofagastaite is transparent and colourless, with vitreous lustre. It is brittle; the Mohs’ hardness isca3. Cleavage is distinct on (001).Dmeas.is 2.42(1) andDcalc.is 2.465 g cm−3. Antofagastaite is optically biaxial (–), α = 1.489(2), β = 1.508(2), γ = 1.510(2) and 2Vmeas.= 40(10)°. The IR spectrum is reported. Chemical composition (wt.%, electron microprobe, H2O determined by gas chromatography) is: Na2O 20.85, CaO 17.42, SO352.56, H2O 7.93, total 98.76. The empirical formula (based on 8 O atoms belonging to sulfate anions per formula unit with all H belonging to H2O molecules) is Na2.06Ca0.95S2.01O8·1.35H2O. Antofagastaite is monoclinic,P21/m,a= 6.4596(4),b= 6.8703(5),c= 9.4685(7) Å, β = 104.580(4)°,V= 406.67(5) Å3andZ= 2. The strongest reflections of the powder XRD pattern [d, Å (I, %) (hkl)] are: 9.17 (100) (001), 5.501 (57) (011), 3.437 (59) (020), 3.058 (43) (003), 2.918 (50) (2¯11), 2.795 (35) (013) and 2.753 (50) (121, 201). The crystal structure was solved based on single-crystal X-ray diffraction data,R1= 5.71%. The structure of antofagastaite consists of ordered and disordered blocks and is related to syngenite K2Ca(SO4)2·H2O. Incorporation of additional H2O molecules in the syngenite-type structure results in disorder of the one of the two tetrahedral sulfate groups occurring in antofagastaite. In addition to the above-reported type material, antofagastaite together with syngenite and blödite occurs in the Arsenatnaya fumarole, Tolbachik volcano, Kamchatka, Russia.

Über zwei Modifikationen von "Tl2Cl3"-valenzgemischten Thallium(I)-hexahalogenothallaten(III) Tl3 [TlCl6] / On Two Modifications of "Tl2Cl3"-Mixed Valence Thallium(I)-hexahalogenothallates(III)

1980 ◽  
Vol 35 (11) ◽  
pp. 1366-1372 ◽  
Author(s):  
Reinhild Böhme ◽  
Jörg Rath ◽  
Bernd Grunwald ◽  
Gerhard Thiele
Keyword(s):  
Crystal Structure ◽  
Raman Spectra ◽  
Diffraction Data ◽  
Mixed Valence ◽  
Three Dimensional ◽  
The Other ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Thallium Chloride

The mixed valence thallium chloride "Tl2Cl3" is polymorphous. Raman spectra and comparable lattice translations suggest similar structures of both modifications. The crystal structure of the rhombic α-Tl2Cl3 crystallizing in yellow, needle-shaped crystals, has been determined from three-dimensional X-ray diffraction data. The unit cell with cell parameters a= 1474.8(5) pm, b - 2508.7(6) pm and c = 1267.6(2) pm contains 16 formula units distributed on 24 independent atom positions. The compound is a mixed valence thallium(I)-hexachlorothallate(III) Tl3[TlCl6] because three of the nine independent Tl atoms are surrounded octahedrally by CI atoms in distances of 250-265 pm, while the other Tl atoms have seven, eight or nine CI neighbours variing between 306 and 383 pm.β-Tl3[TlCl6] forms pale yellow thin platelets and crystallizes monoclinic with cell parameters a = 2549.4(13) pm, 6 = 1469.9(8) pm, c = 1308.5(12) pm and β = 108.58°.

Crystal structure of Bis(tri-2-pyridylamine)iron(II) diperchlorate

1978 ◽  
Vol 31 (1) ◽  
pp. 53 ◽  
Author(s):  
ES Kucharski ◽  
WR McWhinnie ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Metal Atom ◽  
Title Compound ◽  
Complex Cation ◽  
X Ray Diffraction ◽  
Tridentate Ligands ◽  
X Ray ◽  
The One

The crystal structure of the title compound, [Fe((C5H4N)3N)2] (ClO4)2, has been determined by single-crystal X-ray diffraction at 295 K and refined by least squares to a residual of 0.059 (1995 'observed' reflections). Crystals are monoclinic, P21/a, a 12.815(4), b 17.503(7), c 8.318(3) Ǻ, β 121.38(3)°, Z 2. The complex cation lies with the metal atom on a centre of symmetry, the metal being six-coordinate, so that only one of the tridentate ligands is crystallographically independent. The geometry about the metal atom deviates only trivially from octahedral, <N-Fe-N> within the one ligand being 88.1°. <Fe-N> is 1.982 Ǻ.

The Crystal Structure of Indospicine Hydrochloride Hydrate

1992 ◽  
Vol 45 (6) ◽  
pp. 1021 ◽  
Author(s):  
MP Hegarty ◽  
CHL Kennard ◽  
KA Byriel ◽  
G Smith
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Amino Acid ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
A Cell ◽  
Independent Molecules ◽  
The One

The crystal structure of the hepatotoxic amino acid indospicine [L-6-amidino-2-aminohexanoic acid, (S)-2,7-diamino-7-iminoheptanoic acid], as its hydrochloride hydrate, has been determined by X-ray diffraction and refined to a residual R 0.036 for 845 observed reflections collected at 173 K. Crystals are orthorhombic, space group P 22121 with 8 molecules in a cell of dimensions a 5.1541(4), b 14.083(1), c 31.781(3) � . The structure is consistent with the one previously derived from chemical data but with the presence of a terminal amidinium ion and an α-amino acid zwitterion pair. The two independent molecules in the asymmetric unit are conformationally different and form a head-to-tail packing motif linked by NH(amidino)…O(carboxyl) hydrogenbonds (N…O,2.80, 2.85 � ). The structure also features extensive hydrogen bonding involving the water of solvation.

scholarly journals Structure and Stability of the Stoichiometric Al3Fe Phase

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1322
Author(s):  
Zheng Xia ◽  
Bin Wen ◽  
Changzeng Fan
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Enthalpy Of Formation ◽  
First Principles ◽  
First Principles Calculations ◽  
Structural Refinement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma

A disordered stoichiometric Al3Fe phase was obtained when synthesizing Al8Fe3 by the spark plasma sintering (SPS) approach and its crystal structure was determined by the single-crystal X-ray diffraction (SXRD) techniques. The refined structure is an isotype of the reported Al5Fe2 phase, only different in the site occupation factors (s. o. f.) of Al2 and Al3 atoms, which was refined to be 0.431 (13) and 0.569 (13), respectively. Stimulated by the structural refinement results, an ordered stoichiometric Al3Fe phase was established. First-principles calculations reveal that the ordered Al3Fe phase is mechanically and dynamically stable and has a much lower value of enthalpy of formation than any other proposed Al3Fe phases, although it is also metallic and metastable.

Crystal structure of Bis(tri-2-pyridylamine)cobalt(II) diperchlorate

1978 ◽  
Vol 31 (12) ◽  
pp. 2647 ◽  
Author(s):  
ES Kucharski ◽  
WR McWhinnie ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
High Spin ◽  
Metal Atom ◽  
Title Compound ◽  
Coordination Geometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
The One

The crystal structure of the title compound, [Co((C5H4N)3N)2] (ClO4)2, has been determined by single-crystal X-ray diffraction at 295(1) K, i.e. in its pseudo-'high-spin' form, and refined by least squares to a residual of 0.061 for 4639 'observed' reflections. Crystals are monoclinic, P21/a, a 12.811(7), b 17.644(7), c 8.375(4) Ǻ, β 120.15(3)°, Z 2. Whereas in the iron(II) ('low-spin') analogue, the metal atom coordination geometry deviates only trivially from octahedral (<Fe-N> 1.982 Ǻ, <N-Fe-N> within the one ligand 88.1°), in the present compound Co-N ranges from 2.100(2) to 2.152(2) Ǻ and the intraligand N-Co-N angles range from 84.86(7) to 86.09(8)°.

Triethanolaminate iron perchlorate revisited: change of space group, chemical composition and oxidation states in [Fe7(tea)3(tea-H)3](ClO4)2 (tea-H3 is triethanolamine)

2018 ◽  
Vol 74 (2) ◽  
pp. 125-130
Author(s):  
Jitschaq A. van der Horn ◽  
Martin Lutz
Keyword(s):  
Crystal Structure ◽  
Mixed Valence ◽  
Oxidation States ◽  
Group Symmetry ◽  
Original Publication ◽  
Space Group ◽  
X Ray ◽  
Space Groups ◽  
New Space ◽  
Group Chemical

The X-ray crystal structure of tris[N-(2-hydroxyethyl)-2,2′-iminodiethanolato]tris(2,2′,2′′-nitrilotriethanolato)tetrairon(II)triiron(III) bis(perchlorate), [Fe7(C6H12NO3)3(C6H13NO3)3](ClO4)2 or [Fe7(tea)3(tea-H)3](ClO4)2 (tea-H3 is triethanolamine), is known from the literature [Liu et al. (2008). Z. Anorg. Allg. Chem. 634, 778–783] as a heptanuclear coordination cluster. The space group was given as I213 and is reinvestigated in the present study. We find a new space-group symmetry of Pa\overline{3} and could detect O—H hydrogens, which were missing in the original publication. Consequences on the Fe oxidation states are investigated with the bond-valence method, resulting in a mixed-valence core of four FeII and three FeIII centres. Symmetry relationships between the two space groups and the average supergroup Ia\overline{3} are discussed in detail.

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