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

Crystal structure of Hexakis(hydroxylamine-N)nickel(II) sulphate

1974 ◽  
Vol 27 (3) ◽  
pp. 503 ◽  
Author(s):  
LM Engelhardt ◽  
PWG Newman ◽  
CL Raston ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Title Compound ◽  
Heavy Atom ◽  
Crystal Data ◽  
Heavy Atom Method ◽  
Block Diagonal

The crystal structure of the title compound, [Ni(NH20H)6] SO4, has been determined at 298 K by photographic methods; the structure was solved by the heavy atom method and refined by block diagonal least-squares procedures to a residual of 0.095 (1166 independent reflections). Crystal data: triclinic, PI, a 14.026(3), b 6.741(2), c 6.358(1) �, α-98.35(2), β 79.57(1), γ 95.06(2)�, Z 2. In the two crystallographically independent centrosymmetric cations, the nickel atoms are octahedrally coordinated by the ligand nitrogen atoms, (Ni-N), 2.12 �, <N-O), 1.44 �. The Ni-N-O angles range from 110 to 117�. The sulphate geometry is normal and undistorted.

Crystal structure of N-(2,6-dimethylphenyl)chloromaleinimide

1989 ◽  
Vol 54 (9) ◽  
pp. 2408-2414 ◽  
Author(s):  
Viktor Vrábel ◽  
Eleonóra Kellö ◽  
Jan Lokaj ◽  
Václav Konečný
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Least Squares Method ◽  
Heavy Atom ◽  
Diagonal Matrix ◽  
Lattice Parameters ◽  
Block Diagonal Matrix ◽  
Orthorhombic System ◽  
Heavy Atom Method ◽  
Block Diagonal

The crystal structure of N-(2,6-dimethylphenyl)chloromaleinimide solved by the heavy atom method was refined by the 9 x 9 block-diagonal matrix least-squares method to a final R value 0.08 for 1 147 observed diffractions. The compound crystallizes in the orthorhombic system with Pbca group and lattice parameters a = 13.622(4), b = 13.483(7), c = 12.768(6) Å, Z = 8. Monomeric units, between which interactions of type Cl···H-C and O···H-C occured, formed the crystal structure. Both moieties of the molecule, i.e. the phenyl and the five-membered maleinimide rings were found to be virtually planar and the central planes intersecting these rings form an angle 78.3°.

Crystal Structure of Adeninium Trichloromercurate(II),

1975 ◽  
Vol 53 (15) ◽  
pp. 2345-2350 ◽  
Author(s):  
Monique Authier-Martin ◽  
André L. Beauchamp
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Least Squares ◽  
Title Compound ◽  
Heavy Atom ◽  
Chloride Ions ◽  
Water Molecules ◽  
Hydrogen Atoms ◽  
Space Group ◽  
Heavy Atom Method

The title compound belongs to space group P21/c with a = 23.99(1), b = 4.245(2), c = 25.98(1) Å, β = 117.58(7)°, and Z = 8. The structure was solved by the heavy-atom method and refined by block-diagonal least squares on 2589 independent observed reflections. All non-hydrogen atoms were refined anisotropically and some of the hydrogen atoms were located but their parameters were not refined. The final values of R and Rw were 0.042 and 0.047, respectively.The two nonequivalent mercury atoms have very similar environments. Two short Hg—Cl bonds (2.34–2.38 Å) at ∼ 165° define a quasi-molecular HgCl2 unit. Overall octahedral coordination is completed with two chloride ions at 2.76–2.84 Å and two chlorine atoms at 3.19–3.26 Å on neighboring HgCl2 quasi-molecules. HgCl6 octahedra share edges to form twofold ribbons in the b direction. This pattern of octahedra is identical with the onereported for β-NH4HgCl3. The cations are pairs of N(1)-protonated adenine molecules linked by two N(10)—H(10)… N(7) hydrogen bonds and stacked in the b direction. Water molecules act as acceptors in moderately strong hydrogen bonds with acidic protons H(1) and H(9) of adeninium ions. Other generally weaker hydrogen bonds exist between the various parts of the structure.

Studies on tellurium-carbon bonded compounds. II. The crystal structure of [Heptane-3,5-dionato(2 - )]tellurium(II) ('1,1′-Dimethylacetylacetone tellurium(II)')

1977 ◽  
Vol 30 (3) ◽  
pp. 487 ◽  
Author(s):  
JC Dewan ◽  
J Silver
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Title Compound ◽  
Heavy Atom ◽  
Chair Conformation ◽  
Heterocyclic Ring ◽  
Monoclinic Space Group ◽  
Hydrogen Atoms ◽  
Full Matrix ◽  
Heavy Atom Method

The structure of the title compound has been determined by the heavy- atom method from 973 reflections, measured with a diffractometer, and refined by full-matrix least-squares methods to R 0.030. Crystals are monoclinic, space group P21, a = 8.69(1), b = 4.86(1), c = 10.14(2) Ǻ, β = 98.7(1)�, Z = 2. In the discrete molecules of the complex a tellurium(II) atom is bonded to one bivalent heptane-3,5-dione ligand through the α-carbon atoms [Te-C 2.184(6), 2.206(7) Ǻ; C-Te-C 89.7(3)�], forming a heterocyclic ring of chair conformation with the methyl substituents both in equatorial positions. The molecules are arranged in a zig-zag polymeric manner about the 21 axes at x = 0 and z = 0. All hydrogen atoms have been located.

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.

scholarly journals Studies of azo and azoxy dyestuffs. Part 17. Synthesis and structure determination of isomeric α and β phenylazoxypyridines, N-oxides, and methiodides. A reexamination of the oxidation of phenylazopyridines and X-ray structure analyses of 4-(phenyl-α-azoxy)pyridinium methiodide and 4-(phenyl-β-azoxy)pyridine-N-oxide

1984 ◽  
Vol 62 (8) ◽  
pp. 1628-1639 ◽  
Author(s):  
E. Buncel ◽  
S. R. Keum ◽  
M. Cygler ◽  
K. I. Varughese ◽  
G. I. Birnbaum
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Inductive Effect ◽  
Heavy Atom ◽  
Direct Methods ◽  
X Ray ◽  
Proton Donors ◽  
Structure Determinations ◽  
Heavy Atom Method

In an extension of Wallach rearrangement studies into the phenylazoxypyridine series, an investigation of 4-, 3-, and 2-phenylazoxypyridines, the N-oxides, and methiodides is reported. Oxidation of 4- and 3-phenylazopyridine with peracetic acid gives rise to the α and β phenylazoxypyridine-N-oxides, contrary to previous literature reports on the obtention solely of the α isomers. 2-Phenylazopyridine, however, yields only the 2-(phenyl-α-azoxy)pyridine-N-oxide. These results are rationalized on the basis of field, resonance, and steric effects. An unprecedented reactivity difference has been observed in the reactions of the α,β isomers of phenylazoxypyridines under conditions of the Wallach rearrangement. This reactivity difference permits the isolation of the α-azoxy isomers from the α,β mixtures. Unequivocal confirmation of the structures has been obtained from X-ray crystal structure determinations of two representative compounds in this series, viz. 4-(phenyl-β-azoxy)pyridine-N-oxide (11) and 4-(phenyl-α-azoxy)pyridinium methiodide (12), which itself was formed by deoxygenation of 4-(phenyl-α-azoxy)pyridine-N-oxide, followed by methylation with methyl iodide. The crystal structure of 11 was solved by direct methods and refined by block-diagonal least squares to R = 0.041 for 2479 observed reflections. The asymmetric unit contains two independent molecules, both of which are planar. The structure of 12 was determined by the heavy-atom method and refined by full-matrix least squares to R = 0.043 for 1718 observed reflections. The molecules are not planar, the pyridine ring being rotated by 36.5° from the phenylazoxy plane. Evidence is presented for the existence of intramolecular [Formula: see text] and [Formula: see text] bonds in crystal structures of trans-azoxyarenes. The carbon atoms involved in these hydrogen bonds are ortho to the azoxy group and can act as proton donors as a result of the inductive effect of the adjacent nitrogen.

Flukicides. IV. Crystal and Molecular Structure of 3'-Chloro-4'(p-chlorophenoxy)-3,5-diiodo-salicylanilide (Rafoxanide)

1980 ◽  
Vol 33 (1) ◽  
pp. 203 ◽  
Author(s):  
A Sindt ◽  
M Mackay
Keyword(s):  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Carbonyl Oxygen ◽  
Aromatic Rings ◽  
Hydrogen Atoms ◽  
Molecular Hydrogen Bond ◽  
Anisotropic Temperature ◽  
Orthorhombic Crystals ◽  
Temperature Factors ◽  
Heavy Atom Method

Orthorhombic crystals of rafoxanide, C19H11Cl2I2NO3, belong to the space group Pca21 with a 23.234(2), b 8.980(2), c 9.582(2)Ǻ and Z 4. The structure was solved by the heavy-atom method from diffractometer data measured with Mo Kα radiation. Refinement with anisotropic temperature factors given to the non-hydrogen atoms converged at R 0.059 for the 2025 observed terms. The two aromatic rings of the salicylanilide moiety are almost coplanar with a dihedral angle of 11.2°, whereas they are approximately perpendicular to the plane of the phenoxy group. Weak inter-molecular hydrogen-bond-like interactions between the nitrogen and carbonyl oxygen, which involve a glide motif, link the molecules into ribbons extending along the c axis.

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

The crystal structure of BiOCl

1993 ◽  
Vol 205 (1) ◽  
Author(s):  
K. G. Keramidas ◽  
G. P. Voutsas ◽  
P. I. Rentzeperis
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Thermal Parameters ◽  
Full Matrix ◽  
Anisotropic Temperature ◽  
Computer Controlled ◽  
Cl Atoms ◽  
Temperature Factors ◽  
Isosceles Triangles

AbstractThe crystal structure of BiOCl has been redetermined with 3570 observed reflections of which 174 were unique measured on a computer controlled Philips PW 1100 single crystal diffractometer. The structure belongs to the tetragonal space groupThe positional and thermal parameters, with anisotropic temperature factors, were refined by full-matrix least-squares calculations to a finalEach Bi atom is eight-coordinated by 4 O and 4 Cl atoms at distances of 2.316 Å and 3.059 Å respectively thus forming a decahedron. The faces of the decahedron are 2 rectangles (O–O–O–O and Cl–Cl–Cl–Cl) with sides 3.487 Å and 8 isosceles triangles (four O–Cl–O and four Cl–O–Cl) with sides O–Cl 3.249 Å and O–O or Cl–Cl 3.487 Å.The decahedra are linked to each other by a common O–Cl edge along the

Crystal structure of tris(o-phenylenethiourea)selenium(II) bromide pentahydrate, C21H18N6S3Br2Se•5H2O

1986 ◽  
Vol 64 (3) ◽  
pp. 477-480 ◽  
Author(s):  
Sp. Chidambaram ◽  
G. Aravamudan ◽  
G. C. Rout ◽  
M. Seshasayee
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Least Squares ◽  
Heavy Atom ◽  
Title Complex ◽  
Dinuclear Complex ◽  
Water Molecules ◽  
Triclinic Space Group ◽  
Synthesis And Crystal Structure ◽  
Heavy Atom Method

The synthesis and crystal structure of the title complex are reported. Crystals are triclinic, space group [Formula: see text] with a = 10.359(2), b = 10.742(2), and c = 13.604(2) A, α = 87.25(1), β = 88.89(1), γ = 83.63(2)°, and Z = 2. The structure was solved by the heavy atom method and refined by least squares to final R and Rw of 0.055 and 0.06 for 1707 unique reflections. The structure is comprised of planar [Se2(o-phenylenethiourea)6]4+ ions and bromide counterions with the water molecules providing extensive lattice stabilization through hydrogen bonding. The dinuclear complex arises by the fusion of two SeS4 trapezoids with each Se bonded strongly to two terminal sulfur atoms Se—S(1) = 2.306(4), Se—S(3) = 2.286(5) Å and weakly to two other bridging sulfur atoms Se—S(2) = 2.840(5) and Se—S(2)′ = 2.852(5) Å.

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