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.

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 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.

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 'calcium sulphosilicate', Ca5(SiO4)2SO4

1974 ◽  
Vol 27 (3) ◽  
pp. 657 ◽  
Author(s):  
PD Brotherton ◽  
JM Epstein ◽  
MW Pryce ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Title Compound ◽  
Lattice Parameters ◽  
Crystal Data ◽  
Full Matrix ◽  
Lime Kiln

The crystal structure of the title compound, obtained as a coating from a lime kiln, has been shown to be isostructural with that of the mineral silicocarnotite and refined by full-matrix least-squares methods (570 independent diffractometer reflections). The lattice parameters of the latter compound were used to initiate the procedure, the final residual being 0.042. The correspondence in detail between the two structures is close. Crystal data: orthorhombic, Pcmn, a = 10.182(1), b = l5.398(2), c = 6.8500(9) �, Z = 4.

Crystal structure of Iodobis(1,10-phenanthroline)copper(II) iodide octasulphur

1977 ◽  
Vol 30 (9) ◽  
pp. 1965 ◽  
Author(s):  
TW Hambley ◽  
CL Raston ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Title Compound ◽  
Significant Interaction ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Pass Through

The crystal structure of the title compound, [Cu(C12H8N2)2I]I,S8, has been determined by X-ray diffraction at 295(1) K and refined by least squares to R 0.066 (2031 ?observed? reflections). ��� Crystal data: orthorhombic, Pbcb, a 7.984(5), b 16.690(4), c 22.986(12) Ǻ, Z 4. ��� The structure comprises five-coordinate trigonal bipyramidal [Cu(phen)2I]+ cations (I equatorial) lying on the 2 axes parallel to a which pass through the Cu-I bonds, together with iodide anions, and lattice S8 molecules, also lying on 2 axes but parallel to b. In the cation, Cu-I is 2.672(3), Cu-N (equatorial) 2.10(1) and Cu-N (axial) 2.00(1) Ǻ. S-S ranges from 2.004(7) to 2.059(7). There appears to be no significant interaction between the octasulphur molecules and any other species.

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.

scholarly journals Redetermination of tetramethyl tetrathiafulvalene-2,3,6,7-tetracarboxylate

2012 ◽  
Vol 68 (8) ◽  
pp. o2354-o2355 ◽  
Author(s):  
Felix Katzsch ◽  
Edwin Weber
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Heavy Atom ◽  
Direct Methods ◽  
Data Set ◽  
Compound C ◽  
Heavy Atom Method

An improved crystal structure of the title compound, C14H12O8S4, is reported. The structure, previously solved using the heavy-atom method (R= 7.1%), has now been solved using direct methods. Due to the improved quality of the data set anRvalue of 2.06% could be achieved. In the crystal, C—H...S and C—H...O contacts link the molecules.

The synthesis, crystal and molecular structure of 1,1,3,3-tetramethylimidazolidinium diiodide methylene dichloride solvate, (C7H18N2)I2•CH2Cl2

1984 ◽  
Vol 62 (9) ◽  
pp. 1662-1665 ◽  
Author(s):  
Masood A. Khan ◽  
Clovis Peppe ◽  
Dennis G. Tuck
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Title Compound ◽  
Nmr Spectra ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Space Group ◽  
Simple Preparation ◽  
Methylene Dichloride ◽  
Heavy Atom Method

A simple preparation of the title compound, its crystal structure, and nmr spectra are reported. The compound crystallizes in the space group P21/n, with a = 8.109(2) Å, b = 16.183(4) Å, c = 11.968(4) Å, β = 93.45(2)°, V = 1567.7(7) Å−3, ρ = 1.987 g cm−3, Z = 4 (MoKα, λ = 0.71069 Å). The structure was solved by the heavy atom method and refined to the final R = 0.0415 for 1261 "observed" reflections. The structure consists of five-membered cyclic C7H18N22+ cations, iodide anions, and methylene dichloride molecules which are held loosely in the lattice.

Crystal structure of Hydroxyimino(N,N'-dimethyl)malonamide

1977 ◽  
Vol 30 (9) ◽  
pp. 1929 ◽  
Author(s):  
SR Hall ◽  
CL Raston ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Title Compound ◽  
Direct Methods ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Independent Molecules

The crystal structure of the title compound, namely hydroxyimino(N,N?- dimethyl)malonamide (MeNHCOC(=NOH)CONHMe), has been determined by single-crystal X-ray diffraction with diffractometer data at 295 K. The structure was solved by direct methods and refined by least squares to a residual of 0.055 for 1477 observed reflections. ��� Crystal data: monoclinic, P21/n, a 15.508(3), b 10.544(2), c 9.377(1) Ǻ, β 103.15(2)�, Z 8. ��� The two crystallographically independent molecules exhibit little conjugation throughout the C-C-C skeleton (<C-C> 1.50 Ǻ), the molecule being non-planar. <C=O> is 1.234, <N-CH3> 1.443, <OC-N> 1.323, <C-NO> 1.278 and (N-O) 1.375 Ǻ. The geometry is compared with those observed for several related derivatives.

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