Crystal chemistry of the variscite and metavariscite groups: Crystal structures of synthetic CrAsO4⋅2H2O, TlPO4⋅2H2O, MnSeO4⋅2H2O, CdSeO4⋅2H2O and natural bonacinaite, ScAsO4⋅2H2O

2020 ◽  
Vol 84 (4) ◽  
pp. 568-583 ◽  
Author(s):  
Uwe Kolitsch ◽  
Matthias Weil ◽  
Vadim M. Kovrugin ◽  
Sergey V. Krivovichev
Keyword(s):  
Crystal Structures ◽  
Crystal Chemistry ◽  
Electrode Materials ◽  
Structural Formula ◽  
Structure Type ◽  
Hydrothermal Conditions ◽  
Space Group ◽  
Cell Parameters ◽  
Group Type ◽  
Potential Electrode

AbstractWe report the crystal structures of four synthetic members of the variscite group (space group type Pbca) and of bonacinaite, the first naturally occurring scandium arsenate member of the metavariscite group. All structures were determined using single-crystal X-ray intensity data. The following members were all synthesised under either mild hydrothermal conditions or by wet-chemical methods (<90°C). CrAsO4⋅2H2O (deep green): a = 8.894(2), b = 9.946(2), c = 10.206(2) Å and V = 902.8(3) Å3; R1 = 2.14%. Tl3+PO4⋅2H2O (colourless): a = 10.2848(7), b = 8.8578(6), c = 10.3637(7) Å and V = 944.14(11) Å3 (data at –173°C); R1 = 2.56%. MnSeO4⋅2H2O (pale pink): a = 10.441(2), b = 9.2410(18), c = 10.552(2) Å and V = 1018.1(3) Å3; R1 = 2.19%. A different method of preparation of MnSeO4⋅2H2O yielded crystals with very similar unit-cell parameters, a = 10.4353(5), b = 9.2420(5) and c = 10.5349(6) Å; R1 = 2.25%. CdSeO4⋅2H2O (colourless) has a = 10.481(1), b = 9.416(1), c = 10.755(1) Å and V = 1061.4(2) Å3; R1 = 1.53%. The thermal behaviour of the two selenate members was studied by a combination of DSC and TG, supplemented by PXRD. Bonacinaite (IMA2018-056), metavariscite-type natural (Sc,Al)(As,P)O4⋅2H2O (ideally ScAsO4⋅2H2O), crystallises in the space group P21/n, with a = 5.533(1), b = 10.409(2), c = 9.036(2) Å, β = 91.94(3)° and V = 520.11(18) Å3; R1 = 3.66%. The structural formula, supported by chemical analysis, is (Sc0.807(1)Al0.193)(As0.767(7)P0.233)O4⋅2H2O. All structures are based on frameworks built by corner-sharing of TO4 tetrahedra (T = P5+, As5+ or Se6+) with MO4(H2O)2 (M = Mn2+, Cd2+, Cr3+, Sc3+ or Tl3+) octahedra. The flexible frameworks are reinforced by partly bifurcated, strong to weak hydrogen bonds.The crystal chemistry of all known synthetic and natural members of the variscite and metavariscite groups is discussed and compared, and the relative stabilities are evaluated. With the aid of the COMPSTRU program (Bilbao Crystallographic Server), a quantitative comparison of the crystal structures in both groups is given. Calculations of the structural and topological complexity reveal that the metavariscite structure type is structurally and topologically simpler than that of variscite. It is suggested that metavariscite and phosphosiderite are metastable kinetically stabilised phases, in contrast to thermodynamically stable variscite and strengite, respectively. The 3D frameworks of the members of both groups have been shown to be potential electrode materials for rechargeable Li ion batteries.

Crystal chemistry and nomenclature of rhodonite-group minerals

2019 ◽  
Vol 83 (6) ◽  
pp. 829-835 ◽  
Author(s):  
Nadezhda V. Shchipalkina ◽  
Igor V. Pekov ◽  
Nikita V. Chukanov ◽  
Cristian Biagioni ◽  
Marco Pasero
Keyword(s):  
Crystal Chemistry ◽  
Structural Formula ◽  
Structure Type ◽  
Mineral Species ◽  
Triclinic Space Group ◽  
Space Group ◽  
International Mineralogical Association ◽  
Mineralogical Association ◽  
General Chemical

AbstractThis paper presents the nomenclature of the rhodonite group accepted by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA). An overview of the previous studies of triclinic (space group P$\bar{1}$) pyroxenoids belonging to the rhodonite structure type, with a focus on their crystal chemistry, is given. These minerals have the general structural formula VIIM(5)VIM(1)VIM(2)VIM(3)VIM(4)[Si5O15]. The following dominant cations at the M sites are known at present: M(5) = Ca or Mn2+, M(1–3) = Mn2+; and M(4) = Mn2+ or Fe2+. In accordance with the nomenclature, the rhodonite group consists of three IMA-approved mineral species having the following the general chemical formulae: M(5)AM(1–3)B3M(4)C[Si5O15], where A = Ca or Mn2+; B = Mn2+; and C = Mn2+ or Fe2+. The end-member formulae of approved rhodonite-group minerals are as follows: rhodonite CaMn3Mn[Si5O15]; ferrorhodonite CaMn3Fe[Si5O15]; and vittinkiite MnMn3Mn[Si5O15].

Die Kristallstrukturen der Palladium(II)-Komplexe [Pd(CH3CN)4](BF4)2, [PdCl(μ2 -PPh2)(HPPh2)]2 · CH2Cl2 und [PdCl(HPPh2) {H(OPPh2)2}] / The Crystal Structures of the Palladium(II) Complexes [Pd(CH3CN)4](BF4)2, [PdCl(μ2-PPh2)(HPPh2)] · CH2Cl2, and [PdCl(HPPh2){H(OPPh2)2}]

1992 ◽  
Vol 47 (11) ◽  
pp. 1505-1512 ◽  
Author(s):  
Thorsten Gebauer ◽  
Gerlinde Frenzen ◽  
Kurt Dehnicke
Keyword(s):  
Crystal Structures ◽  
Phosphorus Atom ◽  
Palladium Atom ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Bond Lengths ◽  
Group Type ◽  
Polymorphic Forms ◽  
Ray Methods

The crystal structures of the title compounds were solved by X-ray methods.[Pd(CH3CN)4](BF4)2: Space group Pbca, Z = 4,812 observed unique reflections, R = 0.057, wR = 0.033. Lattice dimensions at -80 °C: α = 1027.5(5), b = 1242.8(6), c = 1280.3(6) pm. The compound consists of planar [Pd(CH3CN)4]2+ ions with Pd-N bond lengths of 195.6 pm and BF4- anions.[PdCl(μ2-PPh2(HPPh2)]2 • CH2Cl2 crystallizes in two polymorphic forms in the same space group type but with different cell parameters, which depends on the conditions of the synthesis. α-form: Space group P21/c, Z = 4, 4680 observed unique reflections, R = 0.041, wR = 0.033. Lattice dimensions at -80 °C: a = 937.2(2), b = 1750.3(6), c = 1593.9(5) pm, β = 106.32(2)°. β-form: Space group Ρ21/n, Ζ = 4, 2519 observed unique reflections, R = 0.105, wR = 0.067. Lattice dimensions at -80 °C: a = 1118.0(4), b = 1222.4(3), c = 1849.9(4) pm, β = 90.72(2)°. Both polymorphs contain centrosymmetric molecules [PdCl μ2- PPh2)(HPPh2)]2 with Pd-P bond lengths of 226.6 pm for the bridging PPh2 groups and Pd-P bond lengths of 232.2 pm for the terminal HPPh2 ligands.[PdCl(HPPh2){H(OPPh2)2}]: Space group Pbca, Z = 8,3673 observed unique reflections, R = 0.038, wR = 0.032. Lattice dimensions at -80 °C: a = 1736.6(3), b = 1874.4(4), c = 1983.1(4) pm. The palladium atom has planar coordination consisting of the chlorine atom, the phosphorus atom of the HPPh2 ligand (Pd-P bond length 235.5 pm), and by the two phosphorus atoms of the H(OPPh2)2 chelate (Pd-P bond lengths 225.9 and 231.0 pm).

scholarly journals Syntheses, Raman spectroscopy and crystal structures of alkali hexafluoridorhenates(IV) revisited

2018 ◽  
Vol 74 (5) ◽  
pp. 646-649 ◽  
Author(s):  
James Louis-Jean ◽  
Samundeeswari Mariappan Balasekaran ◽  
Dean Smith ◽  
Ashkan Salamat ◽  
Chien Thang Pham ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Solid State ◽  
Bond Length ◽  
Crystal Structures ◽  
Raman Spectra ◽  
Structure Type ◽  
State Structure ◽  
Space Group ◽  
Group Type ◽  
Distorted Octahedral

The A 2[ReF6] (A = K, Rb and Cs) salts are isotypic and crystallize in the trigonal space group type P\overline{3}m1, adopting the K2[GeF6] structure type. Common to all A 2[ReF6] structures are slightly distorted octahedral [ReF6]2− anions with an average Re—F bond length of 1.951 (8) Å. In those salts, symmetry lowering on the local [ReF6]2− anions from Oh (free anion) to D 3d (solid-state structure) occur. The distortions of the [ReF6]2− anions, as observed in their Raman spectra, are correlated to the size of the counter-cations.

scholarly journals Crystal-to-Crystal Transformation from K2[Co(C2O4)2(H2O)2]·4H2O to K2[Co(μ-C2O4)(C2O4)]

2021 ◽  
Vol 7 (6) ◽  
pp. 77
Author(s):  
Bin Zhang ◽  
Yan Zhang ◽  
Guangcai Chang ◽  
Zheming Wang ◽  
Daoben Zhu
Keyword(s):  
Hydrogen Bond ◽  
Physical Properties ◽  
Crystal Structures ◽  
Molecular Crystal ◽  
Trigonal Prism ◽  
Space Group ◽  
Cell Parameters ◽  
Oxalate Anion ◽  
Crystal Transformation ◽  
Antiferromagnetic Ordering

Crystal-to-crystal transformation is a path to obtain crystals with different crystal structures and physical properties. K2[Co(C2O4)2(H2O)2]·4H2O (1) is obtained from K2C2O4·2H2O, CoCl2·6H2O in H2O with a yield of 60%. It is crystallized in the triclinic with space group P1 and cell parameters: a = 7.684(1) Å, b = 9.011(1) Å, c = 10.874(1) Å, α = 72.151(2)°, β = 70.278(2)°, γ = 80.430(2)°, V = 670.0(1) Å3, Z = 2 at 100 K. 1 is composed of K+, mononuclear anion [Co(C2O4)2(H2O)22−] and H2O. Co2+ is coordinated by two bidentated oxalate anion and two H2O in an octahedron environment. There is a hydrogen bond between mononuclear anion [Co(C2O4)2(H2O)22−] and H2O. K2[Co(μ-C2O4)(C2O4)] (2) is obtained from 1 by dehydration. The cell parameters of 2 are a = 8.460(5) Å, b = 6.906 (4) Å, c = 14.657(8) Å, β = 93.11(1)°, V = 855.0(8) Å3 at 100 K, with space group in P2/c. It is composed of K+ and zigzag [Co(μ-C2O4)(C2O42−]n chain. Co2+ is coordinated by two bisbendentate oxalate and one bidentated oxalate anion in trigonal-prism. 1 is an antiferromagnetic molecular crystal. The antiferromagnetic ordering at 8.2 K is observed in 2.

scholarly journals New crystal structures of adenylate kinase fromStreptococcus pneumoniaeD39 in two conformations

2014 ◽  
Vol 70 (11) ◽  
pp. 1468-1471
Author(s):  
Trung Thanh Thach ◽  
Sangho Lee
Keyword(s):  
Crystal Structures ◽  
Adenylate Kinase ◽  
Bound States ◽  
Critical Role ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
Space Group ◽  
Cell Parameters ◽  
Ligand Free ◽  
Adenylate Kinases

Adenylate kinases (AdKs; EC 2.7.3.4) play a critical role in intercellular homeostasis by the interconversion of ATP and AMP to two ADP molecules. Crystal structures of adenylate kinase fromStreptococcus pneumoniaeD39 (SpAdK) have recently been determined using ligand-free and inhibitor-bound crystals belonging to space groupsP21andP1, respectively. Here, new crystal structures of SpAdK in ligand-free and inhibitor-bound states determined at 1.96 and 1.65 Å resolution, respectively, are reported. The new ligand-free crystal belonged to space groupC2, with unit-cell parametersa= 73.5,b= 54.3,c= 62.7 Å, β = 118.8°. The new ligand-free structure revealed an open conformation that differed from the previously determined conformation, with an r.m.s.d on Cαatoms of 1.4 Å. The new crystal of the complex with the two-substrate-mimicking inhibitorP1,P5-bis(adenosine-5′-)pentaphosphate (Ap5A) belonged to space groupP1, with unit-cell parametersa= 53.9,b= 62.3,c= 63.0 Å, α = 101.9, β = 112.6, γ = 89.9°. Despite belonging to the same space group as the previously reported crystal, the new Ap5A-bound crystal contains four molecules in the asymmetric unit, compared with two in the previous crystal, and shows slightly different lattice contacts. These results demonstrate that SpAdK can crystallize promiscuously in different forms and that the open structure is flexible in conformation.

Crystal data for NH(CH3)3GeCl3

1982 ◽  
Vol 15 (2) ◽  
pp. 247-248 ◽  
Author(s):  
A. Möller ◽  
J. Felsche
Keyword(s):  
High Temperature ◽  
Phase Change ◽  
Perovskite Structure ◽  
Room Temperature ◽  
Structure Type ◽  
Crystal Data ◽  
Space Group ◽  
Cell Parameters ◽  
Orthorhombic Modification ◽  
High Temperature Form

NH(CH3)3GeCl3, C3H10N+.Ge2+.3Cl−, crystallizes at room temperature in an orthorhombic modification with a = 9.537(2), b = 8.235(2), c = 12.138(2) Å, Z = 4, space group Cmc21. These cell parameters correspond to a derivative of the cubic perovskite structure type, with a≃b≃\sqrt{2} a cubic and c≃ 2a cubic. Unlike other chlorogermanates(II) there is not a phase change to an ionically conducting cubic high-temperature form.

scholarly journals New Compounds RE(Zn,Al)8 and Yb4Zn20.3Al12.7 and their Crystal Structures

2006 ◽  
Vol 61 (7) ◽  
pp. 779-784 ◽  
Author(s):  
Ol’ga Stel’makhovych ◽  
Yurij Kuz’ma
Keyword(s):  
Intermetallic Compound ◽  
Crystal Structures ◽  
Structure Type ◽  
Type Structure ◽  
Space Group ◽  
X Ray ◽  
Structure Space ◽  
New Compounds ◽  
First Time ◽  
The Relationship

The crystal structures of several new compounds have been determined using X-ray analysis. The intermetallic compound HoZn5Al3 (a = 8.586(3), c = 16.538(5) Å , RF = 0.0413, RW = 0.0521) has its own structure type (space group I4/mmm), which has been found for the first time. The following compounds are isostructural with the previous one: YZn5.52Al2.48 (a = 8.6183(1), c = 16.5048(3) Å , RI = 0.078, RP = 0.116), DyZn4.96Al3.04 (a = 8.5887(1), c = 16.5002(3) Å , RI = 0.077, RP = 0.114), ErZn5.37Al2.63 (a = 8.5525(2), c =16.3997(5) Å , RI = 0.081, RP = 0.111), TmZn5.64Al2.36 (a = 8.70429(8), c = 16.3943(4) Å , RI = 0.088, RP = 0.095), LuZn5.58Al2.42 (a = 8.5616(1), c= 16.3052(3) Å , RI =0.081, RP =0.101). The intermetallic compound Yb4Zn20.3Al12.7 (a = 8.6183(1), c = 16.5048(3) Å , RI = 0.085, RP = 0.112) adopts the Yb8Cu17Al49 - type structure (space group I4/mmm). The relationship between the HoZn5Al3-type and the Yb8Cu17Al49-type structures is discussed.

A monotitanate with a stuffed cristobalite structure type

1994 ◽  
Vol 9 (2) ◽  
pp. 146-147 ◽  
Author(s):  
C. Colbeau-Justin ◽  
A. Elfakir ◽  
M. Quarton
Keyword(s):  
Solid State ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Solid State Reaction ◽  
Structure Type ◽  
Unit Cell ◽  
Powder Diffraction Data ◽  
Unit Cell Parameters ◽  
Space Group ◽  
Cell Parameters

A new titanate K2ZnTiO4 has been synthesized by solid-state reaction. This compound is isostructural with K2ZnGeO4, space group Pca21, Z=8. Unit-cell parameters were determined: a=11.3352(6) Å, b=5.6352(5) Å, c=16.0125(13) Å, and V=1022.8(3) Å3. Powder diffraction data are reported.

scholarly journals Contributions to the stereochemistry of zirconium oxysalts—part III: syntheses and crystal structures of M2+Zr(SO4)3 with M = Mg, Mn, Co, Ni, Zn and Cd, and a note on (Fe3+,2+,Zr)2(SO4)3 and Fe2(SO4)3

2019 ◽  
Vol 150 (11) ◽  
pp. 1877-1892
Author(s):  
Gerald Giester ◽  
Dominik Talla ◽  
Manfred Wildner
Keyword(s):  
Mixed Valence ◽  
Structure Type ◽  
Minor Amount ◽  
The Novel ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
Space Group ◽  
A Minor ◽  
Zirconium Oxysalts ◽  
Oxygen Bond

Abstract The novel compounds M2+Zr(SO4)3 with M = Mg, Mn, Co, Ni, Zn, and Cd as well as (Fe3+,2+,Zr)2(SO4)3 were synthesized at mild hydrothermal conditions (Teflon-lined stainless steel vessels, 220 °C) from the mixtures of Zr2O2(CO3)(OH)2, the respective M2+(SO4)·nH2O hydrated salts, H2SO4 and a minor amount of water. Crystals up to several tenths of a mm in size were obtained within a few days and studied at 200 K by single-crystal X-ray diffraction techniques. All these compounds belong to the structure type of monoclinic Fe2(SO4)3; they are either isotypic in space group P21/n (No. 14), Z = 4, i.e. M2+Zr(SO4)3 with M = Mn, Co, Ni, Zn, and Cd as well as the mixed valence sulfate (Fe3+,2+,Zr)2(SO4)3 or in the case of MgZr(SO4)3, closely related but with a larger unit cell, in space group Pc and Z = 8. The framework of the monoclinic Fe2(SO4)3 structure is characterized by two types of isolated Fe3+O6 octahedra, corner-linked with three types of sulfate groups. In the isotypic M2+Zr(SO4)3 series, the Fe3+ atom on the Fe(1) position is substituted by Zr4+ while M2+ ions occupy the Fe(2) site in the ferric sulfate structure type. Mean cation-oxygen bond lengths (S[4]: 1.462–1.472 Å; Zr[6]: 2.053–2.060 Å as well as M2+–O distances) are generally rather short, but still within the range reported in literature. Graphic abstract

The crystal structure of trisodium hexachlororhodate (Na3RhCl6)

2018 ◽  
Vol 33 (1) ◽  
pp. 62-65
Author(s):  
Martin Etter
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Structure Type ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

Commercially available trisodium hexachlororhodate (Na3RhCl6) was dehydrated and characterized by laboratory X-ray powder diffraction. The crystal structure is isostructural to the Na3CrCl6 structure type with space group P$\bar 31$c. Unit-cell parameters are a = 6.8116(1) Å, c = 11.9196(2) Å, V = 478.95(2) Å3, and Z = 2.

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