scholarly journals Hidden and apparent twins in uranyl-oxide minerals agrinierite and rameauite: a demonstration of metric and reticular merohedry

2021 ◽  
Vol 54 (6) ◽  
Author(s):  
Jakub Plášil ◽  
Václav Petříček ◽  
Radek Škoda ◽  
Nicolas Meisser ◽  
Anatoly V. Kasatkin
Keyword(s):  
Structure Refinement ◽  
Monoclinic Space Group ◽  
Type I ◽  
Type Ii ◽  
Current Investigation ◽  
Single Crystal Diffraction ◽  
Space Group ◽  
Unit Cells ◽  
Oxide Minerals ◽  
Diffraction Patterns

In this work, the structures of chemically related uranyl-oxide minerals agrinierite and rameauite have been revisited and some corrections to the available structure data are provided. Both structures were found to be twinned. The two minerals are chemically similar, and though their structures differ considerably, their unit-cell metrics are similar. Agrinierite was found to be twinned by metric merohedry (diffraction type I), whereas the structure of rameauite is twinned by reticular merohedry (diffraction type II). The twinning of the monoclinic unit cells (true cells) leads to pseudo-orthorhombic or pseudo-tetragonal supercells in the single-crystal diffraction patterns of both minerals. According to the new data and refinement, agrinierite is monoclinic (space group Cm), with a = 14.069 (3), b = 14.220 (3), c = 13.967 (3) Å, β = 120.24 (12)° and V = 2414.2 (12) Å3 (Z = 2). The twinning can be expressed as a mirror in (101) (apart from the inversion twin), which leads to a supercell with a = 14.121, b = 14.276, c = 24.221 Å and V = 2 × 2441 Å3, which is F centered. The new structure refinement converged to R = 3.54% for 6545 unique observed reflections with I > 3σ(I) and GOF = 1.07. Rameauite is also monoclinic (space group Cc), with a = 13.947 (3), b = 14.300 (3), c = 13.888 (3) Å, β = 118.50 (3)° and V = 2434.3 (11) Å3 (Z = 2). The twinning can be expressed as a mirror in (101) (apart from the inversion twin), which leads to a supercell with a = 14.223, b = 14.300, c = 23.921 Å and V = 2 × 2434 Å3, which is C centered. The new structure refinement of rameauite converged to R = 4.23% for 2344 unique observed reflections with I > 3σ(I) and GOF = 1.48. The current investigation documented how peculiar twinning can be, not only for this group of minerals, and how care must be taken in handling the data biased by twinning.

scholarly journals Chirality control of the Quadruple helixes of the metal strings

2014 ◽  
Vol 70 (a1) ◽  
pp. C1032-C1032
Author(s):  
Chung-Han Yu ◽  
Min-Shiang Kuo ◽  
Ching-Yi Chuang ◽  
Gene-Hsiang Lee ◽  
Bih-Yaw Jin ◽  
...  
Keyword(s):  
Mixed Valence ◽  
Monoclinic Space Group ◽  
Cd Spectra ◽  
Trans Form ◽  
Single Crystal Diffraction ◽  
Triclinic Space Group ◽  
Space Group ◽  
Pentadentate Ligands ◽  
Chirality Control ◽  
Similar Unit

Novel chiral pentadentate ligands with naphthyridine and camphorsulfonyl groups have been designed and used to control the chirality of quadruple helixes of metal strings directly:Δ-Ni5((-)camnpda)4 (1) and Λ-Ni5((+)camnpda)4 (2). Compound 1 is a Δ form metal string complex with H2(-)camnpda and 2 is Λ form one with H2(+)camnpda. By X-ray single-crystal diffraction, The structures of the compound 1 and 2 are both 2,2-trans form in the same monoclinic space group C2 and have the similar unit cell. Further, it demonstrates that two metal strings are chiral isomers each other by CD spectra. In theoretical computation, the local minimum (Λ-Ni5((+)camnpda)4 with the Δ form) becomes energetically unfavourable by about 100 kcal/mol due to the strong steric repulsion introduced by the camphor groups. Finally, the racemic crystal is obtained with a 1:1 mixture of compounds 1 and 2 in triclinic space group P-1. Both the external dinickel distance in 1 and 2, about 2.280 Å, and the SQUID experiment reveal mixed valence [Ni2]3+ characters and the magnetic behaviors are anti-ferromagnetic (J = -55.0 cm-1 for 1 and -63.3 cm-1 for 2). In the electrochemistry, the three reversible oxidation waves in 1 and 2 are -0.13, 0.20 and 0.97 V.

X-ray powder diffraction data for three red azo pigments: sodium, barium, and ammonium lithol salts

2017 ◽  
Vol 32 (3) ◽  
pp. 187-192 ◽  
Author(s):  
Alicja Rafalska-Łasocha ◽  
Marta Grzesiak-Nowak ◽  
Piotr Goszczycki ◽  
Katarzyna Ostrowska ◽  
Wiesław Łasocha
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Monoclinic Space Group ◽  
Powder Diffraction Data ◽  
Space Group ◽  
X Ray ◽  
Space Groups ◽  
Cell Parameters ◽  
Synthesis Procedure ◽  
Diffraction Patterns

Lithol reds belong to the group of azo pigments, which were popular artists’ colouring materials in the first half of the twentieth century. These pigments were also used in many branches of industry. Here, we report X-ray powder diffraction data, unit-cell parameters, and space groups for three compounds from this group: sodium (E)-2-((2-hydroxynaphthalen-1-yl)diazenyl)naphthalene-1-sulphonate monohydrate (Na lithol red), monoclinic, space group C2/c, with cell parameters a = 33.343(7), b = 6.667(2), c = 16.397(4) Å, β = 90.83°, V = 3644.51 Å3, Z = 8; barium (E)-2-[(2-hydroxynaphthalen-1-yl)diazenyl]naphthalene-1-sulphonate trihydrate (Ba lithol red), monoclinic, space group P21/m, with cell parameters a = 17.758(9), b = 6.209(4), c = 16.857(8) Å, β = 92.07°, V = 1857.39 Å3, Z = 2; and ammonium (E)-2-[(2-hydroxynaphthalen-1-yl)diazenyl]naphthalene-1-sulphonate monohydrate (NH4 lithol red), monoclinic, space group P2/c, with cell parameters a = 17.721(5), b = 6.428(3), c = 16.911(5) Å, β = 100.31(3)°, V = 1895.31 Å3, and Z = 4. In the first and third cases we synthesised the pigments in their monohydrate form, performed X-ray powder diffraction measurements, and indexed all of the obtained diffraction maxima. In the case of the barium compound, despite many efforts in the course of the synthesis procedure, the powder diffraction patterns of the obtained samples were not of the best quality. Nevertheless, we indexed the best one and found a reliable space group and cell parameters.

X-ray powder diffraction data for five lanthanoid chromates [Ln2(CrO4)3(H2O)5]·2H2O (Ln=La,Pr,Nd,Sm,Eu)

1994 ◽  
Vol 9 (2) ◽  
pp. 98-104
Author(s):  
Jaakko Leppä-aho ◽  
Jussi Valkonen
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Powder Diffraction Data ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Diffraction Patterns

X-ray powder diffraction data are reported for a series of isomorphous compounds of [Ln2(CrO4)3(H2O)5]·2H2O, where Ln=La, Pr, Nd, Sm, or Eu. The compounds crystallize in monoclinic space group P21/c (No: 14) with Z=4. Refined unit cell parameters and indexed powder diffraction patterns are given.

Aspidolite, the Na analogue of phlogopite, from Kasuga-mura, Gifu Prefecture, central Japan: description and structural data

2005 ◽  
Vol 69 (6) ◽  
pp. 1047-1057 ◽  
Author(s):  
Y. Banno ◽  
R. Miyawaki ◽  
T. Kogure ◽  
S. Matsubara ◽  
T. Kamiya ◽  
...  
Keyword(s):  
Structural Data ◽  
Miscibility Gap ◽  
Monoclinic Space Group ◽  
Contact Aureole ◽  
Central Japan ◽  
Space Group ◽  
International Mineralogical Association ◽  
Cell Parameters ◽  
Diffraction Patterns ◽  
Two Phases

AbstractAspidolite, the Na analogue of phlogopite, ideally NaMg3AlSi3O10(OH)2, occurring in hornfels from a contact aureole in Kasuga-mura, central Japan, has been approved as a mica species by the Commission on New Minerals and Mineral Names of the International Mineralogical Association. Aspidolite is interleaved with and surrounded by phlogopite. Based on its mode of occurrence, phlogopite is classified into two types; (1) phlogopite interleaved with aspidolite (= interleaved phlogopite) and (2) phlogopite rim. The aspidolite-phlogopite assemblage is associated with amphibole (pargasite-magnesiosadanagaite), titanite, calcite, scapolite, apatite, pyrrhotite and chalcopyrite. A representative chemical formula of aspidolite is (Na0.90K0.10)∑1.00(Mg2.27Al0.41Fe0.232+Ti0.05)∑2.96 (Al1.44Si2.56)∑4.00O10(OH1.97F0.03)∑2.00. Aspidolite has almost fully occupied the interlayer site; its Na/(Na+K) ratio ranges from 0.67 to 0.95. It has more tetrahedral Al (1.38—1.48 a.p.f.u. for O = 11) than the ideal aspidolite end-member showing progression of tschermakite-type substitution. The alternation of aspidolite and phlogopite parallel to the (001) plane may indicate a miscibility gap between these two phases. The phlogopite rim is interpreted as a later product, probably formed metasomatically. Aspidolite is optically biaxial negative with elongation positive and Z ‖ cleavage. Two polytypes (1M and 1A) of aspidolite were identified in X-ray powder diffraction patterns. Aspidolite-1M is monoclinic, space group C2/m, with refined unit-cell parameters a = 5.291(8), b = 9.16(2), c = 10.12(2) Å, β = 105.1(1)°, V = 473(1) Å3, Z = 2. Aspidolite-1A is triclinic, space group C1̄ , with a = 5.289(6), b = 9.16(1), c = 9.892(9) Å, α = 94.45(9), β = 97.74(9), γ = 90.0(1)°, V = 473.4(9) Å3, Z = 2.

[Ni3Se(o-C6H4{CH2Se}2)3]2- und [Ni4(SeiC3H7)8], die ersten höherkernigen NickeI(II)-Komplexe mit vollständiger Selen-Ligandensphäre [Ni3Se(o-C6H4{CH2Se}2)3]2- and [Ni4(SeiC3H7)8], the First Polynuclear Nickel(II) Complexes with Complete Selenium Ligand Spheres

1997 ◽  
Vol 52 (12) ◽  
pp. 1501-1509 ◽  
Author(s):  
Arnd Müller ◽  
Gerald Henkel
Keyword(s):  
Complex Anion ◽  
Structure Refinement ◽  
Structural Features ◽  
Monoclinic Space Group ◽  
Triclinic Space Group ◽  
Space Group ◽  
Tetranuclear Complex ◽  
Midpoint Potential

Reaction of nickel(II) chloride with disodium ο-xylenediselenolate in methanol yields the trinuclear mixed selenide-selenolate complex anion [Ni3Se(ο-C6H4{CH2Se}2)3]2- (3) which was isolated both as tetramethylammonium and mixed sodium/tetraethylammonium salt of formula [Me4N]2[Ni3Se(ο-C6H4{CH2Se}2)3] · MeOH (1) and [Et4N]3Na[Ni3Se-(ο-C6H4{CH2Se}2)3]2- · 3MeOH · 3H2O (2), respectively. Crystals of 1 are triclinic, space group P1̄, a = 9.065(2), b = 13.281(3); c = 18.019(4) Å , α = 92.81(2), β = 97.55(2), γ = 105.09(2)° and Z = 2. 2 crystallizes in the rhom bohedral space group R3c with a = 20.305(5), c = 41.709(9) Å and Z = 6. The structures were refined to R = 0.0705 (1) and 0.0794 (2), respectively. Both compounds contain the complex anion [Ni3Se- (ο-C6H4{CH2Se}2)3]2- (3), which possesses the same principal structural features as the corresponding thiolato derivatives. Reaction of nickel(II) chloride with sodium iso-propane selenolate in methanol leads to the cyclic tetranuclear complex [Ni4(SeiC3H7)8] (4), which crystallizes in the monoclinic space group P2/n with a = 13.161(3), b = 10.464(2), c = 14.603(2) Å , β = 94.42(1)° and Z = 2. The structure refinement converged to R = 0.0541. 4 is isostructural with the corresponding thiolato compound. The introduction of selenium instead of sulfur ligands reduces the midpoint potential of the reversible metal-centered oxidation from +595 to +285 mV.

Au3SnCuP10 and Au3SnP7: Preparation and Crystal Structures of Au3Sn Heterocluster Polyphosphides

2006 ◽  
Vol 61 (7) ◽  
pp. 871-881 ◽  
Author(s):  
Stefan Lange ◽  
Tom Nilges
Keyword(s):  
Transition Metal ◽  
Crystal Structures ◽  
Homologous Series ◽  
Structure Refinement ◽  
Chair Conformation ◽  
Lattice Parameter ◽  
Lattice Parameters ◽  
Monoclinic Space Group ◽  
Space Group ◽  
Tetrahedral Voids

The formation of Au3Sn heteroclusters completes the homologous series of M3Sn clusters observed for transition metal main-group polyphosphides. Au3SnCuP10 is cubic, space group F4̅3̅m (No. 216) with lattice parameter a = 10.3953(5) Å . The structure refinement yielded R1 = 0.0353 and wR2 = 0.0726 for 154 F2 values and 13 variables. Disordered Au3Sn heteroclusters occupy all octahedral, and adamantane like P10 cages one half of the tetrahedral voids of a face-centred cubic ( fcc) arrangement of copper. Ordered and orientationally disordered Au3Sn heteroclusters have been observed for Au3SnP7, embedded in a 1∞ [P7] polyphosphide unit formed by six-membered phosphorus rings in chair conformation which are linked by a P-bridge. Au3SnP7 is monoclinic, space group P21/m (No. 11) with lattice parameters of a = 6.219(2), b = 10.836(2), c = 6.318(2) Å , β = 108.65(2)°, V = 403.4(2) Å3, R1 = 0.0412 and wR2 = 0.0745, 1261 F2 values and 56 variables. Au3SnP7 with disordered Au3Sn clusters has slightly larger lattice parameters of a = 6.343(3), b = 10.955(3), c = 6.372(3) Å , β = 108.63(2)°, V = 419.6(2) Å3, R1 = 0.0324 and wR2 = 0.0691, 1131 F2 values and 58 variables.

K and Ba distribution in the structures of the clathrate compounds KxBa16−x(Ga,Sn)136(x= 0.8, 4.4, and 12.9) and KxBa8−x(Ga,Sn)46(x= 0.3)

2013 ◽  
Vol 69 (4) ◽  
pp. 319-323 ◽  
Author(s):  
Marion C. Schäfer ◽  
Svilen Bobev
Keyword(s):  
Cell Volume ◽  
Unit Cell Volume ◽  
Unit Cell ◽  
Type I ◽  
Type Ii ◽  
Space Group ◽  
Clathrate Compounds ◽  
Anisotropic Displacement Parameters ◽  
Good Agreement

Studies of the K–Ba–Ga–Sn system produced the clathrate compounds K0.8(2)Ba15.2(2)Ga31.0(5)Sn105.0(5)[a= 17.0178 (4) Å], K4.3(3)Ba11.7(3)Ga27.4(4)Sn108.6(4)[a= 17.0709 (6) Å] and K12.9(2)Ba3.1(2)Ga19.5(4)Sn116.5(4)[a= 17.1946 (8) Å], with the type-II structure (cubic, space groupFd\overline{3}m), and K7.7(1)Ba0.3(1)Ga8.3(4)Sn37.7(4)[a= 11.9447 (4) Å], with the type-I structure (cubic, space groupPm\overline{3}n). For the type-II structures, only the smaller (Ga,Sn)24pentagonal dodecahedral cages are filled, while the (Ga,Sn)28hexakaidecahedral cages remain empty. The unit-cell volume is directly correlated with the K:Ba ratio, since an increasing amount of monovalent K occupying the cages causes a decreasing substitution of the smaller Ga in the framework. All three formulae have an electron count that is in good agreement with the Zintl–Klemm rules. For the type-I compound, all framework sites are occupied by a mixture of Ga and Sn atoms, with Ga showing a preference for Wyckoff site 6c. The (Ga,Sn)20pentagonal dodecahedral cages are occupied by statistically disordered K and Ba atoms, while the (Ga,Sn)24tetrakaidecahedral cages encapsulate only K atoms. Large anisotropic displacement parameters for K in the latter cages suggest an off-centering of the guest atoms.

Crystal structure refinement of sahlinite Pb14(AsO4)2O9Cl4

2003 ◽  
Vol 67 (1) ◽  
pp. 15-21 ◽  
Author(s):  
E. Bonaccorsi ◽  
M. Pasero
Keyword(s):  
Crystal Structure ◽  
Diffraction Data ◽  
Structure Refinement ◽  
Lone Pair ◽  
Monoclinic Space Group ◽  
Crystal Structure Refinement ◽  
Single Crystal Diffraction ◽  
Coordination Polyhedra ◽  
Synchrotron Facility ◽  
Derivatives Of

AbstractThe crystal structure of sahlinite [Pb14(AsO4)2O9Cl4] from Lågban (Sweden) has been refined up to R = 0.071 using single-crystal diffraction data collected at the Elettra synchrotron facility. Sahlinite is monoclinic, space group C2/c, with a = 12.704(4), b = 22.576(5), c = 11.287(4) Å, β = 118.37(3)°. Sahlinite is isostructural with kombatite, its vanadium counterpart. Both are derivatives of the litharge form of PbO. In the structure of sahlinite there are seven independent Pb atoms, which are linked to Cl and/or O atoms, with coordination number ranging from V to VIII. The coordination polyhedra are irregularly shaped, due to the 6s2 lone-pair effect displayed by Pb2+.

Neutron powder diffraction data for low- and high-temperature NASICON phases of LiM2(PO4)3 (M=Hf, Sn)

1999 ◽  
Vol 14 (1) ◽  
pp. 53-60 ◽  
Author(s):  
E. Morin ◽  
T. Le Mercier ◽  
M. Quarton ◽  
E. R. Losilla ◽  
M. A. G. Aranda ◽  
...  
Keyword(s):  
High Temperature ◽  
Rietveld Method ◽  
Structure Refinement ◽  
Powder Diffraction Data ◽  
Space Group ◽  
Neutron Powder Diffraction Data ◽  
Reversible Phase Transition ◽  
Structural Skeleton ◽  
Diffraction Patterns ◽  
Reversible Phase

The new diffraction patterns of the low- and high-temperature phases of Li0.87Hf2.032(PO4)3 and LiSn2(PO4)3 are given and indexed on the basis of a structure refinement from neutron powder data using Rietveld method. The two isotypic compounds present a reversible phase transition: triclinic (LT, space group P1¯) ⇄ rhombohedral (HT, space group R3¯c) which proceeds by topotactic distortion of the structural skeleton.

Hydrogen bonding in hydroxypyridium salts

2018 ◽  
Vol 233 (7) ◽  
pp. 501-506
Author(s):  
Andrei V. Mironov ◽  
Victor A. Tafeenko ◽  
Dmitrii Yu. Grebenkin ◽  
Alexander E. Oblezov
Keyword(s):  
Hydrogen Bonding ◽  
Oxygen Atom ◽  
Single Crystal ◽  
Crystal Structures ◽  
Diffraction Data ◽  
Nitrate Anion ◽  
Single Crystal Diffraction ◽  
Space Group ◽  
X Ray ◽  
Unit Cells

Abstract The crystal structures of 6-methyl-2-ethyl-3-hydroxypyridiniun nitrate (C8H12NO)NO3 (I) and fumarate (C8H12NO)2C4H2O4 (II) were solved and refined from X-ray single crystal diffraction data (CuKα, (I) a=4.6477(2), b=14.5906(9), c=14.5551(8) Å, β=99.100(4)°, space group P21/c, Z=4, Rp/Rwp=0.033/0.047; (II) a=8.8293(3), b=13.4268(5), c=8.3893(3) Å, β=96.303(3)°, space group P21/c, Z=2, Rp/Rwp= 0.034/0.049). Both structures are built of infinite chains along ac diagonal of the unit cells formed by hydrogen bonding between the hydroxypyridium cation and the corresponding anion. Each fumarate anion is linked to four hydroxypyridium cations while nitrate anion is connected with two hydroxypyridium cations only leaving one oxygen atom in the nitrogen group isolated.

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