The crystal and electron structure of O-(2-chloroethyl)-O-isobutyl-O-(2-phenyl-4-methylthio-3-oxo-2H-pyridazine-5-yl) thiophosphate

1987 ◽  
Vol 52 (3) ◽  
pp. 696-706 ◽  
Author(s):  
Viktor Vrábel ◽  
František Pavelčík ◽  
Eleonóra Kellö ◽  
Stanislav Miertuš ◽  
Václav Konečný ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Structure Refinement ◽  
Bond Distance ◽  
Direct Methods ◽  
Electron Structure ◽  
Anisotropic Temperature ◽  
Wiberg Index ◽  
Trigonal Pyramid ◽  
Net Charges ◽  
Temperature Factors

The crystal structure of the title fungicide was solved by direct methods, using Σ2 relationship and tangent formula. The structure refinement was made by full-matrix least-squares with anisotropic temperature factors to the final R = 0.096 for 1 486 significant reflexions. The compound crystallizes in the orthorhombic system, the space group Pccn. The lattice parameters are a = 1.8719(9), b = 3.0426(33), c = 0.7616(2) nm and Z = 8. The intermolecular interactions of types C-H···Cl and C-H···O are observed between the centrosymmetrically related molecules in the crystal structure. The coordination polyhedron around phosphorus is between trigonal pyramid and tetrahedron. The planes of the phenyl and pyridazine rings are rotated through 70° each other. The electron structure was calculated by semiempirical CNDO/2 method. The calculations revealed the most negative net charges on S(2) and O(1). The value of Wiberg index Iw = 1.08 and the bond distance 0.149 nm show that the bond N(1)-C(5) is simple and is not involved in the conjugation.

The crystal and electron structure of N-(2,2,2-trichloro-1-morpholino-ethyl) formamide

1985 ◽  
Vol 50 (8) ◽  
pp. 1619-1628 ◽  
Author(s):  
Viktor Vrábel ◽  
František Pavelčík ◽  
Eleonóra Kellö ◽  
Stanislav Miertuš ◽  
Václav Konečný ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Least Squares Method ◽  
Direct Methods ◽  
Molecular Fragment ◽  
Structure Calculation ◽  
Electron Structure ◽  
Dihedral Angles ◽  
Stable Form ◽  
Anisotropic Temperature ◽  
Diagonal Approximation

The crystal structure was solved by direct methods and refined by the least squares method in a 9 x 9 block diagonal approximation using the anisotropic temperature parameters. The R-factor was decreased to a final value of 5.6% for 970 observed reflextions. The crystals are monoclinic with a space group of P21/c and lattice parameters of a = 1.1056(11), b = 0.8913(11), c = 1.2023(16) nm, β = 96.32°, and Z = 4. The crystal structure consists of discrete molecules between which hydrogen interactions of the N-H...O and C-H...O type were observed. The lengths of the N1-C3 (0.1432 nm) and C3-O1 (0.1203 nm) bonds and valence angles, C3-N1-C1 (119.9°), N1-C3-O1 (126.5°), indicate considerable delocalization of the π-electrons and participation of the lone electrone pair on N1 nitrogen in the conjugation in the N1-C3-O1 molecular fragment. The CNDO/2 quantum chemical method was used to calculate the electron structure. Calculation for partial optimization of the dihedral angles, φ and ω, indicated that the most stable form is obtained for the values φ = 0°, ψ = 120-150°, 240-270° and ω = 150-210°, 330-30°.

Crystal structure of KCaF3 determined by the Rietveld profile method

1997 ◽  
Vol 12 (2) ◽  
pp. 70-75 ◽  
Author(s):  
Alicja Ratuszna ◽  
Michel Rousseau ◽  
Philippe Daniel
Keyword(s):  
Crystal Structure ◽  
Room Temperature ◽  
Lattice Parameters ◽  
Profile Method ◽  
Anisotropic Temperature ◽  
Monoclinic Distortion ◽  
Refinement Procedure ◽  
Watson Statistic ◽  
Temperature Factors ◽  
Atomic Coordinates

Using the Rietveld profile method, the atomic coordinates and anisotropic temperature factors of KCaF3 were refined. At room temperature, KCaF3 crystallizes in monoclinic B21/m symmetry, with the lattice parameters: a=8.754(2) Å, b=8.765(4) Å, c=8.760(5) Å, β=90.48(3)°, V=672.1(3) Å3, Z=8. The refinement procedure was stopped when RB=0.05 and the Durbin–Watson statistic factor=0.85 had been reached. The structure determined is related to the tilting of CaF6 octahedra of the a−b+c− type, which are responsible for the monoclinic distortion in perovskite crystals.

The crystal structure of diamminesilver dinitroargentate, [Ag(NH3)2]Ag(NO2)2*

1977 ◽  
Vol 146 (4-6) ◽  
Author(s):  
H. M. Maurer ◽  
Alarich Weiss
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Heavy Atom ◽  
Anisotropic Temperature ◽  
Light Atoms ◽  
Difference Fourier ◽  
Temperature Factors ◽  
Heavy Atom Method ◽  
Silver Atoms ◽  
Block Diagonal

AbstractThe crystal structure of diamminesilver dinitroargentate, [Ag(NHThe point positions of the silver atoms were obtained by the heavy-atom method whereas those of the light atoms were found by difference Fourier syntheses. Coordinates and anisotropic temperature factors were refined by block-diagonal least-squares methods with the result

Sveinbergeite, Ca(Fe2+6 Fe3+)Ti2(Si4O12)2O2(OH)5(H2O)4, a new astrophyllite-group mineral from the Larvik Plutonic Complex, Oslo Region, Norway: description and crystal structure

2011 ◽  
Vol 75 (5) ◽  
pp. 2687-2702 ◽  
Author(s):  
A. P. Khomyakov ◽  
F. Cámara ◽  
E. Sokolova ◽  
Y. Abdu ◽  
F. C. Hawthorne
Keyword(s):  
Crystal Structure ◽  
Manganese Oxides ◽  
Structure Refinement ◽  
Direct Methods ◽  
Calculated Density ◽  
Group Mineral ◽  
Amateur Mineralogist ◽  
Perfect Cleavage ◽  
Mohs Hardness ◽  
Deep Green

AbstractSveinbergeite, Ca(Fe2+6Fe3+)Ti2(Si4O12)2O2(OH)5(H2O)4, is a new astrophyllite-group mineral discovered in a syenite pegmatite at Buer on the Vesteroya peninsula, Sandefjord, Oslo Region, Norway. The mineral occurs in pegmatite cavities as 0.01—0.05 mm thick lamellar (0.2—0.5×5—10 mm) crystals forming rosette-like divergent groups and spherical aggregates, which are covered by brown coatings of iron (and possibly manganese) oxides, associated with magnesiokatophorite, aegirine, microcline, albite. calcite, fluorapatite, molybdenite, galena and a hochelagaite-like mineral. Crystals of sveinbergeite are deep green with a pale green streak and a vitreous and pearly lustre. Sveinbergeite has perfect cleavage on ﹛001﹜ and a Mohs hardness of 3. Its calculated density is 3.152 g/cm3. It is biaxial positive with α 1.745(2), β 1.746(2), γ 1.753(2), 2V(meas.) = 20(3)°. The mineral is pleochroic according to the scheme Z > X ∽ Y : Z is deep green, X and Y are brownish green. Orientation is as follows: X ┴ L (001), Y ᶺ b = 12°, Z = a, elongation positive. Sveinbergeite is triclinic, space group P1̄, a = 5.329(4), b = 11.803(8), c = 11.822(8) Å; α = 101.140(8)°, β = 98.224(8)°, γ = 102.442(8)°; V = 699.0(8) Å3; Z = 1. The nine strongest lines in the X-ray powder diffraction pattern [d in Å(I)(hkl)] are: 11.395(100)(001,010). 2.880(38)(004), 2.640(31)(2̄10,l̄41), 1.643(24)(07̄1,072), 2.492(20)(2l̄l), 1.616(15)(070), 1.573(14)(3̄2̄2), 2.270(13)(1̄3̄4) and 2.757(12)(1̄40,1̄3̄2). Chemical analysis by electron microprobe gave Nb2O5 0.55, TiO2 10.76, ZrO2 0.48, SiO2 34.41, A12O3 0.34, Fe2O3 5.57, FeO 29.39, MnO 1.27, CaO 3.87, MgO 0.52, K2O 0.49, Na2O 0.27, F 0.24, H2O 8.05, O=F -0.10, sum 96.11 wt.%, the amount of H2O was determined from structure refinement, and the valence state of Fe was calculated from structure refinement in accord with Mossbauer spectroscopy. The empirical formula, calculated on the basis of eight (Si + Al) p.f.u., is (Ca0.95Na0.12K0.14)Σ1.21(Fe2+5.65Fe3+0.93Mn0.25Mg0.18)Σ7.01(Ti1.86Nb0.06Zr0.05Fe3+)Σ2 (Si7091Al0.09)Σ8O34.61H12.34F0.17, Z = 1. The infrared spectrum of the mineral contains the following absorption frequencies: 3588, ∽3398 (broad), ∽3204 (broad), 1628, 1069, 1009, 942, 702, 655 and 560 cm–1. The crystal structure of the mineral was solved by direct methods and refined to an R1 index of 21.81%. The main structural unit in the sveinbergeite structure is an HOH layer which is topologically identical to that in the astrophyllite structure. Sveinbergeite differs from all other minerals of the astrophyllite group in the composition and topology of the interstitial A and B sites and linkage of adjacent HOH layers. The mineral is named in honour of Svein Arne Berge (b. 1949), a noted Norwegian amateur mineralogist and collector who was the first to observe and record this mineral from its type locality as a potential new species.

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 Pb5(As3+O3)Cl7 from the historic slags of Lavrion, Greece – a novel Pb(II) chloride arsenite

2011 ◽  
Vol 75 (2) ◽  
pp. 337-345 ◽  
Author(s):  
O. I. Siidra ◽  
S. V. Krivovichev ◽  
N. V. Chukanov ◽  
I. V. Pekov ◽  
A. Magganas ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Direct Methods ◽  
Structural Features ◽  
Lead Chloride ◽  
Form Complex ◽  
Trigonal Pyramid

AbstractThe crystal structure of new lead chloride arsenite, Pb5(As3+O3)Cl7 [orthorhombic, Pbcn, a = 16.894(2), b = 10.913 (1), c = 16.760(2) Å, V = 3090.1(7) Å3], from the historic slags of Lavrion, Greece, has been solved by direct methods and refined to R1 = 0.069. The structure contains five symmetrically unique Pb, one As, eight Cl and three O sites. The As atom forms three nearly equal As—O bonds which result in the formation of an AsO3 trigonal pyramid with As at the apex. The Pbl. Pb2, Pb3 and Pb4 atoms are bonded to the AsO3 groups via Pb2+—O bonds to form complex [Pb4(AsO3)] chains parallel to the b axis. The Pb(5) atom is coordinated solely by Cl– anions. The resulting Pb(5)Cl7 polyhedra share common edges and corners to produce bent chains parallel to the c axis. A short compilation of structural features of known lead chloride arsenites is given.

Crystal structure of a novel synthetic compound, Pb2O(OH)I, and structure refinement of ‘iodolaurionite’, Pb(OH)I: hydroxo- and oxocentred units in Pb minerals and synthetic compounds

2013 ◽  
Vol 77 (8) ◽  
pp. 3239-3248 ◽  
Author(s):  
O. I. Siidra ◽  
D. Yu. Zenko ◽  
A. N. Suknotova ◽  
S. V. Krivovichev
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Structure Refinement ◽  
Three Dimensional ◽  
Direct Methods ◽  
Hydroxyl Groups ◽  
Synthetic Compound ◽  
Synthetic Compounds ◽  
Hydrothermal Reactions

AbstractYellow needles of 'iodolaurionite', Pb(OH)I, and a novel compound Pb2O(OH)I, have been prepared by hydrothermal reactions of PbO and PbI2 at 170°C. The crystal structure of 'iodolaurionite', Pb(OH)I (orthorhombic, Pnma, a = 7.8244(8), b = 4.2107(4), c = 10.4724(10) Å, V = 345.03(6) Å3, Z = 4) has been refined to R1 = 0.041 for 129 independent observed reflections. The structure is based on the OHPb3 triangles sharing common edges to produce single [OHPb]+ chains extending along the b axis and parallel to the ab plane. The three-dimensional integrity of the structure is provided by the Pb–I bonds and the O–H···I hydrogen bonding. The structure is isotypic with that of laurionite, Pb(OH)Cl. The crystal structure of Pb2O(OH)I (monoclinic, C2/m, a = 13.711(3), b = 4.0975(10), c = 9.584(2) Å, β = 110.64(1)°, V = 503.9(2) Å3, Z = 4), has been solved by direct methods and refined to R1 = 0.053 for 586 independent observed reflections. In the structure of Pb2O(OH)I, O(1)Pb4 tetrahedra link together by sharing edges and corners to form [OPb2]2+ chains similar to those observed in sidpietersite. The O(2) atoms belong to hydroxyl groups attached to both sides of the chains to produce novel [O(OH)Pb2]+ 1D units. The [O(OH)Pb2]+ units are extended parallel to the b axis and lie within the bc plane. The [O(OH)Pb2]+ units are linked together via hydrogen bonding in the (100) plane and by weak Pb–I bonds in the [100] direction. The [O(OH)Pb2]+ bands can be obtained from the [OPb] layer of OPb4 tetrahedra present in the structure of tetragonal PbO (litharge). The continuous [OPb] layer has to be broken into [O2Pb2] bands containing 3- and 4-coordinated O atoms in the 1:1 ratio with subsequent protonation of the 3-coordinated O sites. Relations of Pb(OH)I and Pb2O(OH)I to known Pb hydroxy- and oxyhalides are described briefly.

Crystal structure of praseodymium sulphate octahydrate

1981 ◽  
Vol 155 (3-4) ◽  
Author(s):  
I. S. Ahmed Farag ◽  
M. A. El-Kordy ◽  
N. A. Ahmed
Keyword(s):  
Crystal Structure ◽  
Least Squares Method ◽  
Three Dimensional ◽  
The Other ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Bridging Ligand ◽  
Dimensional Network ◽  
Anisotropic Temperature ◽  
Temperature Factors

AbstractThe crystals of PrThe crystal structure has been determined from three-dimensional single-crystal X-ray diffraction data and refined by the least-squares method, using anisotropic temperature factors, to a discrepancy index ofThe molecules are arranged in layers forming a three-dimensional network. Each Pr atom is coordinated with eight oxygen atoms, four of which are related to sulphate groups, the other four are to water molecules. The sulphate ion, located at the twofold axis, behaves as a bidentate bridging ligand connecting two Pr atoms. The other sulphate ion acts as a threefold bridging ligand between three neighbouring Pr atoms.

Description and crystal structure of domerockite, Cu4(AsO4)(AsO3OH)(OH)3·H2O, a new mineral from the Dome Rock Mine, South Australia

2013 ◽  
Vol 77 (4) ◽  
pp. 509-522 ◽  
Author(s):  
P. Elliott ◽  
U. Kolitsch ◽  
A. C. Willis ◽  
E. Libowitzky
Keyword(s):  
Crystal Structure ◽  
Structure Refinement ◽  
South Australia ◽  
Direct Methods ◽  
New Mineral ◽  
Calculated Density ◽  
Bluish Green ◽  
Distorted Octahedra ◽  
Mohs Hardness ◽  
Greenish Blue

AbstractDomerockite, Cu4(AsO4)2(AsO3OH)(OH)3·H2O, is a new mineral from the Dome Rock Mine, South Australia. It occurs as aggregates of bluish green, equant to short prismatic and tabular crystals up to 0.3 mm long and 0.2 mm across. Domerockite is translucent, with a vitreous lustre and pale green streak. It displays no fluorescence under UV irradiation. The mineral is brittle with an uneven fracture, a Mohs hardness of ∼3 and a calculated density of 4.44 g/cm3 (based on the structure refinement). Optically, it is biaxial negative, with α = 1.798(4), β = 1.814(4), γ = 1.817(4), 2Vcalc. = 46°; pleochroism is very weak; X pale greenish yellow, Y greenish blue, Z greenish blue; absorption X < Y = Z; orientation is uncertain. Chemical analysis by electron microprobe gave CuO 52.04, ZnO 0.78, BaO 0.11, As2O537.67, P2O50.32, SiO20.24, H2O 8.84, total 100.00 wt.%, with H2O calculated by difference. The empirical chemical formula is (Cu3.94, Zn0.06)Σ4.00H0.91(As1.97, P0.03, Si0.02)Σ2.02O8(OH)3.00˙H2O based on 12 oxygen atoms.Domerockite is triclinic, space group P, with a = 5.378(11), b = 8.962(18) c = 9.841(2) Å, α = 75.25(3), β = 83.56(3), γ = 79.97(3)°, V = 450.5(16) Å3 and Z = 2. The eight strongest lines in the X-ray powder diffraction pattern are [d (Å), (I)(hkl)]: 4.716 (30)(101, 002, 111), 3.697 (25)(121), 3.605 (30)(120, 12), 3.119 (60)(12), 3.073 (100)(1), 2.856 (40)(02, 030), 2.464 (50)(212, 13), 2.443 (40)(014). The crystal structure of domerockite has been solved by direct methods and refined to an R index of 7.44% using 2635 observed reflections. The structure comprises [Cuφ4] (φ = O, OH) chains of edge-sharing sharing, distorted octahedra that extend along [10] and are decorated by AsO4 tetrahedra to form sheets in the (010) plane. Dimers of edge-sharing [CuO4(OH)(H2O)] octahedra share corners with dimers of edge-sharing [CuO4(OH)] square pyramids to form zigzag chains which extend along [101]. The chains lie between and link to the sheets by sharings corners of octahedra, square pyramids and tetrahedra to form a heteropolyhedral framework.

The crystal structure of BiTel

1993 ◽  
Vol 204 (1) ◽  
Author(s):  
K. G. Keramidas ◽  
G. P. Voutsas ◽  
A. Papazoglou ◽  
P. I. Rentzeperis
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Three Dimensional ◽  
Full Matrix ◽  
Anisotropic Temperature ◽  
Equilateral Triangles ◽  
Computer Controlled ◽  
Temperature Factors ◽  
Isosceles Triangles

AbstractThe crystal structure of BiTeI has been redetermined with 1924 independent reflections, using three-dimensional intensities measured on a computer controlled Philips PW 1100 single crystal diffractometer. The structure belongs to the rhombohedral space groupThe positional and thermal parameters, with anisotropic temperature factors, were refined by full-matrix least-squares calculations to a finalEach Bi atom is six-coordinated by three Te and three I atoms at distances 3.88(5) Å and 3.05(2) Å respectively thus forming a distorted octahedron. The faces of the octahedron are two equilateral triangles (Te-Te-Te, I-I-I) with sides 4.336 Å and six isosceles triangles (three I-Te-I and three Te-I-Te) with sides I–Te 3.29(3) Å and I–I or Te–Te 4.336 Å.The octahedra are linked to each other by a common Te–I edge along the

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