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.

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.

Lack of a threefold rotation axis in α-Fe2O3and α-Cr2O3crystals

2015 ◽  
Vol 71 (2) ◽  
pp. 203-208 ◽  
Author(s):  
Michał Stękiel ◽  
Radosław Przeniosło ◽  
Izabela Sosnowska ◽  
Andrew Fitch ◽  
Jacek B. Jasiński ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Rotation Axis ◽  
Magnetic Ordering ◽  
Evidence Based ◽  
Space Group ◽  
X Ray ◽  
Space Groups ◽  
Transmission Electron

The crystal structure of α-Fe2O3and α-Cr2O3is usually described with the corundum-type trigonal crystal structure based on the space group R\bar 3c. There are, however, some observations of the magnetic ordering of both α-Fe2O3and α-Cr2O3that are incompatible with the trigonal symmetry. We show experimental evidence based on X-ray powder diffraction and supported by transmission electron microscopy that the symmetry of the crystal structure of both α-Fe2O3and α-Cr2O3is monoclinic and it is described with the space groupC2/c(derived from R\bar 3c by removing the threefold rotation axis). The magnetic orderings of α-Fe2O3and α-Cr2O3are compatible with the magnetic space groupsC2/candC2/c′, respectively. These findings are in agreement with the idea from Curie [(1894),J. Phys.3, 393–415] that the dissymmetry of the magnetic ordering should be associated with a dissymmetry of the crystal structure.

scholarly journals SHELXT– Integrated space-group and crystal-structure determination

2015 ◽  
Vol 71 (1) ◽  
pp. 3-8 ◽  
Author(s):  
George M. Sheldrick
Keyword(s):  
Crystal Structure ◽  
Structure Determination ◽  
Dual Space ◽  
Group Symmetry ◽  
Phase Problem ◽  
Space Group ◽  
Space Groups ◽  
Reflection Data ◽  
Peak Search ◽  
Best Fit

The new computer programSHELXTemploys a novel dual-space algorithm to solve the phase problem for single-crystal reflection data expanded to the space groupP1. Missing data are taken into account and the resolution extended if necessary. All space groups in the specified Laue group are tested to find which are consistent with theP1 phases. After applying the resulting origin shifts and space-group symmetry, the solutions are subject to further dual-space recycling followed by a peak search and summation of the electron density around each peak. Elements are assigned to give the best fit to the integrated peak densities and if necessary additional elements are considered. An isotropic refinement is followed for non-centrosymmetric space groups by the calculation of a Flack parameter and, if appropriate, inversion of the structure. The structure is assembled to maximize its connectivity and centred optimally in the unit cell.SHELXThas already solved many thousand structures with a high success rate, and is optimized for multiprocessor computers. It is, however, unsuitable for severely disordered and twinned structures because it is based on the assumption that the structure consists of atoms.

Oxotitanate mit gemischter Valenz, III Zur Kenntnis von BaTi8O16 / Oxotitanates with Mixed Valence, III About BaTi8O16

1980 ◽  
Vol 35 (3) ◽  
pp. 332-334 ◽  
Author(s):  
J. Schmachtel ◽  
Hk. Müller- Buschbaum
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Mixed Valence ◽  
Vacuum Furnace ◽  
Monoclinic Symmetry ◽  
Unknown Compound ◽  
Space Group ◽  
X Ray

The hitherto unknown compound BaTi8O16 was prepared by heating a mixture of BaO:TiO2 = 1:4 in a vacuum furnace to 1400 °C (Ti crucible).Single crystal X-ray investigations show monoclinic symmetry (a = 1420,9, b = 297,1, c = 998,1 pm, β = 133,50°; space group C23-C2). The crystal structure was found to be isotypic to α-MnO2.

Zur Kristallstruktur von ( Cu , Mn ) UMo3O12/On the Crystal Structure of (Cu, Mn )UMo3O12

1996 ◽  
Vol 51 (3) ◽  
pp. 450-452 ◽  
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Lattice Energy ◽  
Oxidation States ◽  
Hexagonal Symmetry ◽  
Space Group ◽  
X Ray ◽  
Symmetry Space ◽  
Symmetry Space Group

Abstract Single crystals of (Cu,Mn)UMo3O12 have been prepared in sealed copper tubes. X-ray investigations lead to hexagonal symmetry, space group C6h2-P63/m a = 9.7895 (13), c = 6.202(1) Å , z = 2. (Cu,Mn)UMo3O12 is isotypic to CdThMo3O12. Calculations of the Coulomb terms of lattice energy with respect to different oxidation states of copper, molybdenum and uranium and the previously described pair of isotypic compounds of CdThMo3O12 to Na2ThRe6O24 are discussed.

On the space group of garronite

1999 ◽  
Vol 14 (3) ◽  
pp. 190-194 ◽  
Author(s):  
Gilberto Artioli ◽  
Maurizio Marchi
Keyword(s):  
Crystal Structure ◽  
High Resolution ◽  
Natural Zeolite ◽  
Structural Models ◽  
Structure Model ◽  
Powder Diffraction Data ◽  
Monoclinic Structure ◽  
Space Group ◽  
X Ray ◽  
Space Groups

The crystal structure of the natural zeolite garronite from Goble, Oregon has been refined using high resolution synchrotron X-ray powder diffraction data. Garronite has the same tetrahedral aluminosilicate framework as gismondine [GIS], and earlier structural models indicated a strong tetragonal pseudosymmetry. Proposed models in the literature were based on the I4¯m2 and I41/a space groups, on account of symmetry lowering from the topological I41/amd space due to partial cation/water molecule order in the zeolitic cavities. Test structure analysis has been performed in all possible space subgroups including monoclinic space groups, and the refinement has been successfully carried out in space group I2/a (C2/c). The resulting monoclinic structure model is to be preferred over the tetragonal ones on the basis of: (1) lower agreement indices of the refinement; (2) a chemically sound framework geometry; and (3) a more satisfactory interpretation of the Ca atoms coordination in the extraframework cages.

Über die Reduktion von Alkinkomplexen des Molybdäns und Wolframs in hohen Oxidationsstufen. Die Kristallstruktur von MoCl3(THF)3 / On the Reduction of Alkyne Complexes of Molybdenum and Tungsten in High Oxidation States. The Crystal Structure of MoCl3(THF)3

1989 ◽  
Vol 44 (10) ◽  
pp. 1161-1166 ◽  
Author(s):  
Peter Hofacker ◽  
Claus Friebel ◽  
Kurt Dehnicke ◽  
Petra Bäuml ◽  
Wolfgang Hiller ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Ir Spectroscopy ◽  
Oxidation States ◽  
Epr Spectra ◽  
Space Group ◽  
X Ray ◽  
High Oxidation ◽  
Oxygen Sensitive ◽  
Alkyne Complexes ◽  
Ray Methods

The reduction of the tungsten alkyne complexes [WCl4(RC≡CR)]2 (R = Ph, SiMe3) with cobaltocen in THF solutions leads to the complexes [CoCp2]2[WCl4(RC≡CR)]2 (R = Ph (1); R = SiMe3 (2)), as green, oxygen sensitive crystalline powders. Reduction of [WCl4(Me3SiC=CSiMe3)]2 and of [MoCl4(PhC=CPh)]2 with sodium naphthalide in THF solutions in the presence of 15-crown-5 gives [Na-15-crown-5]3[W2Cl9], and MoCl3(THF)3, respectively. All compounds have been characterized by IR spectroscopy, and 1 and 2, in addition, by their EPR spectra. The crystal structure of MoCl3(THF)3 was determined by X-ray methods. Space group P21/c, Z = 4, 2642 observed unique reflexions, R = 0.050. Lattice dimensions at 20 °C: a = 888.4(2), b = 1281.5(3), c = 1535.2(3) pm, β = 92.17(2)°. The compound forms monomeric octahedral molecules with a meridional arrangement of the ligands.

Crystal structure of an inclusion complex between chiral monoaza-15-crown-5 and S(–)-1-phenyl-ethyl ammonium percholorate

2003 ◽  
Vol 218 (5) ◽  
Author(s):  
Süheyla Özbey ◽  
F. B. Kaynak ◽  
M. Toğrul ◽  
N. Demirel ◽  
H. Hoşgören
Keyword(s):  
Crystal Structure ◽  
Inclusion Complex ◽  
Single Crystal ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
New Type

AbstractA new type of inclusion complex, S(–)-1 phenyl ethyl ammonium percholorate complex of R-(–)-2-ethyl - N - benzyl - 4, 7, 10, 13 - tetraoxa -1- azacyclopentadecane, has been prepared and studied by NMR, IR and single crystal X-ray diffraction techniques. The compound crystallizes in space group

scholarly journals Molekül- und Kristallstruktur von 1.1-Dimethylsilylentitanocendichlorid, (CH3)2Si(C5H4)2TiCl2 / Molecular and Crystal Structure of l,r-Dimethylsilylene Titanocene Dichloride, (CH3)2Si(C5H4)2TiCl2

1981 ◽  
Vol 36 (10) ◽  
pp. 1208-1210 ◽  
Author(s):  
Hartmut Köpf ◽  
Joachim Pickardt
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Structure Determination ◽  
Titanocene Dichloride ◽  
Molecular And Crystal Structure ◽  
Monoclinic Space Group ◽  
Crystal Data ◽  
Space Group ◽  
X Ray ◽  
Structural Dimensions

Abstract The molecular structure of the bridged [1]-titanocenophane 1,1'-dimethylsilylene titanocene dichloride, (CH3)2Si(C5H4)2TiCl2, has been investigated by an X-ray structure determination. Crystal data: monoclinic, space group C2/c, Z = 4, a = 1332.9(3), 6 = 988.7(3), c = 1068.9(3) pm, β = 113.43(2)°. The results are compared with the structural dimensions of similar compounds: 1,1'-methylene titanocene dichloride, CH2(C5H4)TiCl2, with the unbridged titanocene dichloride, (C5H5)2TiCl2 and the ethylene-bridged compound (CH2)2(C5H4)2TiCl2

Crystal structure determination of the conformation of two bicyclo[3.3.1]nonan-ones

1985 ◽  
Vol 63 (6) ◽  
pp. 1166-1169 ◽  
Author(s):  
John F. Richardson ◽  
Ted S. Sorensen
Keyword(s):  
Crystal Structure ◽  
Direct Methods ◽  
Chair Conformation ◽  
Molecular Structures ◽  
Boat Conformation ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Final Agreement

The molecular structures of exo-7-methylbicyclo[3.3.1]nonan-3-one, 3, and the endo-7-methyl isomer, 4, have been determined using X-ray-diffraction techniques. Compound 3 crystallizes in the space group [Formula: see text] with a = 15.115(1), c = 7.677(2) Å, and Z = 8 while 4 crystallizes in the space group P21 with a = 6.446(1), b = 7.831(1), c = 8.414(2) Å, β = 94.42(2)°, and Z = 2. The structures were solved by direct methods and refined to final agreement factors of R = 0.041 and R = 0.034 for 3 and 4 respectively. Compound 3 exists in a chair–chair conformation and there is no significant flattening of the chair rings. However, in 4, the non-ketone ring is forced into a boat conformation. These results are significant in interpreting what conformations may be present in the related sp2-hybridized carbocations.

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