Determination of the crystal structure of cobalt(II) orthosilicate

1979 ◽  
Vol 44 (11) ◽  
pp. 3350-3356 ◽  
Author(s):  
Bohumil Kratochvíl ◽  
Jana Podlahová ◽  
Jindřich Hašek
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Least Squares Method ◽  
Structure Type ◽  
Fourier Synthesis ◽  
Independent Reflection ◽  
Full Matrix ◽  
R Factor ◽  
Olivine Structure

The crystal structure of Co2SiO4 (olivine structure type) was solved by Patterson and Fourier synthesis and refined by the full matrix least squares method. A final value of the R factor of 0.057 was obtained from 911 independent reflection intensities. The structure symmetry corresponds to space group Pnma with lattice parameters a = 1032.8(3), b = 601.9(2) and c = 478.2(1) pm. The unit cell contains four formula units. The Si-O distance in isolated SiO4 tetrahedra varies from 162.1(3) to 165.9(3) pm. Both cobalt atoms are octahedrally surrounded by oxygen atoms with Co-O distances of 208.0(3)-223.1(2) pm.

Crystal and molecular structure of 3-ethyl-4-hydroxy-1,2,3(4H)-benzotriazine and 6-chloro-4-hydroxy-3-methyl-4-phenyl-1,2,3-benzotriazine

1985 ◽  
Vol 63 (3) ◽  
pp. 581-585 ◽  
Author(s):  
Kwong Khee Lai ◽  
Carl H. Schwalbe ◽  
Keith Vaughan ◽  
Ronald J. Lafrance ◽  
Clive D. Whiston
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bonds ◽  
Least Squares ◽  
Least Squares Method ◽  
Crystal And Molecular Structure ◽  
Tetrahedral Geometry ◽  
Orthorhombic System ◽  
Full Matrix ◽  
X Ray ◽  
R Factor

The crystal structures of the title compounds have been determined from X-ray data collected on a four-circle diffractometer and refined by the full-matrix least-squares method. The former compound crystallizes in the orthorhombic system, space group Pbcn, with a = 14.346(8), b = 7.239(1), c = 17.276(2) Å, and has been refined to a conventional R factor of 0.043 for 890 observed reflections. Corresponding results for the latter compound are monoclinic, P21/n, a = 12.222(4), b = 7.482(2), c = 14.170(8) Å, β = 94.06(4)°, R = 0.060 for 2128 observed data. The triazine rings of both compounds exhibit short N(1)—N(2) bonds and tetrahedral geometry at C(4); however, the ring is puckered in the first compound but flat in the second. Molecules in both crystals are linked by [Formula: see text] hydrogen bonds.

Crystal Structure of α-VPO5

1973 ◽  
Vol 51 (16) ◽  
pp. 2621-2625 ◽  
Author(s):  
Byron Jordan ◽  
Crispin Calvo
Keyword(s):  
Crystal Structure ◽  
Oxygen Atom ◽  
Least Squares ◽  
Least Squares Method ◽  
Fold Axis ◽  
Full Matrix ◽  
Bond Lengths ◽  
R Value ◽  
A Site ◽  
Vanadium Ion

α-VPO5 crystallizes in the tetragonal space group P4/n with a = 6.014(7) and c = 4.434(2) Å. The structure, isotypic with that of α-VSO5, was refined by full-matrix least-squares method to an R value of 0.089 using 239 independent reflections. The vanadium ion lies on a crystallographic four-fold axis, as does one of the oxygen atoms, and the P on a site of [Formula: see text] symmetry. A second oxygen atom, as a result of disorder, occurs in two positions which are mirror reflected with respect to the ac plane. The structure consists of highly distorted VO6 groups with bond lengths along the c axis of 1.580(11) and 2.853(11) Å while the remaining four V—O bond lengths are all 1.858(8) Å. The P—O bond lengths in the PO4. tetrahedron are 1.541(8) Å with the PO4 groups bridging across four chains of VO6 groups.

The Crystal Structure of cis-Dichloro(2,2′-oxydi-3-butene)platinum(II), PtCl2((CH2=CH—CH(CH3))2O)

1973 ◽  
Vol 51 (4) ◽  
pp. 604-608 ◽  
Author(s):  
J. Hubert ◽  
A. L. Beauchamp ◽  
T. Theophanides
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Platinum Atom ◽  
Double Bonds ◽  
Triclinic Space Group ◽  
Standard Methods ◽  
Full Matrix ◽  
R Factor ◽  
Square Planar ◽  
Coordination Plane

The reaction of K2PtCl4 with CH3—CH=CH—CH2—OH yields the complex cis-[PtCl2((CH2=CH—CH(CH3))2O)]. The crystals are triclinic, space group [Formula: see text], a = 9.420(2) Å, b = 8.359(4) Å, c = 7.837(4) Å, α = 91.10(4)°, β = 62.13(4)°, γ = 80.80(5)°, and Z = 2. The structure, solved by standard methods, has been refined anisotropically by full matrix least-squares methods to a R factor of 0.052 by use of 2441 independent observed reflections. The complex is a monomer, where both double bonds of the diolefin ether are coordinated to the platinum atom as in Zeise's salt. The usual square planar coordination of platinum(II) is completed by two chlorine atoms. The (=CH2) groups of both double bonds are found on the same side of the coordination plane. Various possible conformations of the coordinated ligand in the complex are discussed.

Complexes of the methyl tris(3,5-dimethylpyrazol-1-yl) gallate ligand, MeGa(N2C5H7)3−, and its hydroxy derivative, MeGa(N2C5H7)2(OH)−. Crystal and molecular structure of [MeGa(N2C5H7)2(OH)]Mo(CO)2(η3-C4H7)

1979 ◽  
Vol 57 (2) ◽  
pp. 139-146 ◽  
Author(s):  
Kenneth R. Breakell ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Least Squares ◽  
Structure Determination ◽  
Carbonyl Compounds ◽  
Crystal And Molecular Structure ◽  
Hydroxy Derivative ◽  
Full Matrix ◽  
Sterically Demanding

The synthesis and coordinating properties of the tridentate tris-chelating ligand, methyl tris(3,5-dimethylpyrazol-1-yl)gallate, MeGa(N2C5H7)3−, are described. Carbonyl and nitrosyl carbonyl compounds of manganese, molybdenum, and tungsten incorporating this ligand are detailed. The ready conversion of the above ligand to the less sterically demanding tris-chelating 'hydroxy' ligand [MeGa(N2C5H7)2(OH)]− occurs in attempted syntheses of the 'η3-allyl' complexes, [MeGa(N2C5H7)3]M(CO)2'η3-allyl', (where M = Mo or W, 'η3-allyl' = η3-C3H5, η3-C4H7). The tridentate chelating nature of this 'hydroxy' ligand is conclusively demonstrated in the crystal structure determination of the complex, [MeGa(N2C5H7)2(OH)]-Mo(CO)2(η3-C4H7). Crystals of this complex are monoclinic, a = 14.020(4), b = 10.110(1), c = 15.493(7) Å, β = 111.58(3)°, Z = 4, space group P21/n. The structure was solved by Patterson and Fourier syntheses and was refined by full-matrix least-squares procedures to a final R of 0.40 and Rw of 0.043 for 3374 reflections with I ≥ 3.5σ(I).

Crystal Structure of ζ2' Martensite in Au-49.5at%Cd Alloy

1991 ◽  
Vol 246 ◽  
Author(s):  
Yutaka Emura ◽  
Takuya Ohba ◽  
Kazuhiro Otsuka
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Crystal Lattice ◽  
Least Squares ◽  
Least Squares Method ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Lattice Constants

AbstractCrystal structure of the ζ2' martensite in a Au-49.5at%Cd ally has been analyzed by the single crystal x-ray diffraction method. The crystal lattice was trigonal and the lattice constants were a:0.8095(3) and c=o.57940(6) nm. There were 18 atoms in a unit cell. The space group was P3, which was different from that previously determined by Vatanayon and Hehemann. The structure was refined by the full matrix least squares method to a final R factor of 7.8% and a weighted R factor of 4.1%.

Verfeinerung der Kristallstruktur eines basaltischen Magnesio-Hastingsites

1981 ◽  
Vol 156 (3-4) ◽  
Author(s):  
E. M. Walitzi ◽  
F. Walter
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Least Squares Method ◽  
Three Dimensional ◽  
Full Matrix ◽  
Space Group ◽  
X Ray

AbstractThe crystal structure of the basaltic clino-amphibole magnesio-hastingsite was refined from three-dimensional photographic X-ray data by a full matrix least-squares method in the space group

Die Kristallstruktur des Trichlorphons C4H8O4PCl3

1969 ◽  
Vol 24 (9) ◽  
pp. 1071-1074 ◽  
Author(s):  
E. Höhne ◽  
Kh. Lohs
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Least Squares Method ◽  
Unit Cell ◽  
Fourier Methods ◽  
Space Group ◽  
R Factor ◽  
Anisotropic Temperature ◽  
Temperature Factors ◽  
Atomic Coordinates

The crystal structure of trichlorphon [O,O-Dimethyl- (1-hydroxy-2,2,2-trichlor-äthyl) -phosphonat] has been determined by PATTERSON and FOURIER methods. Space group P212121 with 4 molecules in a unit cell of dimensions α = 8,96 ± 0,03 A, b= 18,60 ± 0,05 Å, c = 5,80 ± 0,02 A were determined. Atomic coordinates and anisotropic temperature factors have been refined by the least squares method. The final R-factor is R (hkl) =0,102.

The Crystal Structure of KAlP2O7

1973 ◽  
Vol 51 (16) ◽  
pp. 2613-2620 ◽  
Author(s):  
Hok Nam Ng ◽  
Crispin Calvo
Keyword(s):  
Crystal Structure ◽  
Spherical Shell ◽  
Bond Length ◽  
Least Squares ◽  
Least Squares Method ◽  
Full Matrix ◽  
Bond Lengths ◽  
The Mean ◽  
R Value ◽  
Oxygen Atoms

KAlP2O7 crystallizes as monoclinic crystals with a = 7.308(8), b = 9.662(6), c = 8.025(4) Å, β = 106.69(7)°, z = 4 and space group P21/c. The structure was refined from 1394 observed reflections by full-matrix least-squares method to a final R value of 0.032. The P2O74− anion consists of a pair of corner-sharing PO4 groups in a nearly staggered configuration. The mean bridging and terminal P—O bond lengths are 1.607 and 1.509 Å, respectively, and the P—O—P angle is 123.2°. The anions lie in planes parallel to (001). The Al ions are bonded to six oxygen atoms contributed by anions in three layers of P2O7 groups. The average Al—O bond length is 1.889 Å. The potassium ion is coordinated to ten oxygen atoms lying within a spherical shell with inner and outer radii of 2.739 and 3.185 Å.

Substituted Ruthenium Triammine Complexes: The Crystal Structure of Triammineaqua(pentane-2,4-dionato)ruthenium(III) Dithionate Dihydrate, [Ru(NH3)3:(acac)(OH2)][S2O6].2H2O

1988 ◽  
Vol 41 (8) ◽  
pp. 1251 ◽  
Author(s):  
AA Diamantis ◽  
PS Moritz ◽  
MR Snow ◽  
ERT Tiekink
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Structure Analysis ◽  
Least Squares Method ◽  
Electrochemical Studies ◽  
Dilute Solution ◽  
Orthorhombic Space Group ◽  
Full Matrix ◽  
Ruthenium Atom ◽  
Species Being

The complex [ Ru (NH3)3( acac )(OH2)]2+ was obtained by the reaction of [ Ru (NH3)3(H2O)3][CF3SO3]3 with pentane-2,4-dione. The crystals are orthorhombic, space group P212121, with a 7.805(4), b 12.997(4), c 17.479(13) Ǻ, U 1773.1 Ǻ3 with Z 4. The structure was refined by a full-matrix least-squares method on 827 reflections [for which I ≥ 2.5σ(I)] to final R 0.042 and Rw 0.043. The structure analysis reveals an almost perfect octahedral coordination around the ruthenium atom with the three ammine ligands attached in a facial arrangement. Spectroscopic and electrochemical studies are consistent with the same species being present in dilute solution.

The crystal chemistry of the amphiboles. III: Refinement of the crystal structure of a sub-silicic hastingsite

1977 ◽  
Vol 41 (317) ◽  
pp. 43-50 ◽  
Author(s):  
F. C. Hawthorne ◽  
H. D. Grundy
Keyword(s):  
Crystal Structure ◽  
Chemical Composition ◽  
Bond Length ◽  
Least Squares ◽  
Crystal Chemistry ◽  
Least Squares Method ◽  
Three Dimensional ◽  
Full Matrix ◽  
Positional Disorder ◽  
The Mean

SummaryThree-dimensional counter-diffractometer data and a full-matrix least-squares method have been used to refine the crystal structure of a sub-silicic hastingsite in the space group C2/m. The chemical composition of the amphibole is with ceil parameters a = 9·8659(4), b = 18·0139(8), c = 5·3545(2)Å, and β = 105·082(1)°. Unit weights were used throughout the refinement and the final R-factor for 1263 observed non-equivalent reflections was 4.1%. The mean tetrahcdral bond length for aluminous amphiboles varies linearly with the total amount of tetrahedral A1. Curves are derived relating individual mean bond lengths with A1 occupancy. The positional disorder on the A-site of the aluminous amphiboles appears to be partly related to the amount of substitution of A1 into the T(2) tetrahedron.

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