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°.

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.

Structure of the Tris(diallyldithiocarbamate)cobalt(III) Complex

1992 ◽  
Vol 57 (2) ◽  
pp. 332-338 ◽  
Author(s):  
Eleonóra Kellö ◽  
Jan Lokaj ◽  
Viktor Vrábel
Keyword(s):  
Least Squares ◽  
Metal Atom ◽  
Least Squares Method ◽  
Heavy Atom ◽  
Distorted Octahedron ◽  
Monoclinic System ◽  
Space Group ◽  
Twofold Axis ◽  
Diagonal Approximation ◽  
Heavy Atom Method

The structure of [Co{S2CN(CH2-CH=CH2)2}3] was determined by the heavy atom method, all nonhydrogen atoms being refined by anisotropic diagonal approximation using the least squares method to the value of R= 0.067 for 1 024 reflections with I ≥ 1.96σ(I). The substance is isostructural with [Fe{S2CN(CH2-CH=CH2)2}3], crystallizes in the monoclinic system, space group C2/c, lattice parameters a = 1.8763(9), b = 1.0209(5), c = 1.5402(7) nm, β = 106.18(4)°, Z = 4. Cobalt is coordinated by 3 dithiocarbamate ligands in the bidentate way, the average Co-S lenght is 0.2267(2) nm. The metal atom and two ligand atoms are located on the twofold axis. The CoS6 polyhedron is a trigonally distorted octahedron.

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.

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.

Crystal and molecular structure of dinickel(II) (S,S)-ethylenediamine-N,N'-disuccinate heptahydrate

1979 ◽  
Vol 44 (4) ◽  
pp. 1070-1079 ◽  
Author(s):  
František Pavelčík ◽  
Viktor Kettmann ◽  
Jaroslav Majer
Keyword(s):  
Complex Anion ◽  
Least Squares Method ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Crystal Water ◽  
Orthorhombic System ◽  
Space Symmetry ◽  
Hexadentate Ligand ◽  
Space Symmetry Group ◽  
Heavy Atom Method

[Ni2(S,S)-EDDS].7 H2O structure has been solved by the heavy atom method and by the least squares method at R = 0.058; the substance crystallizes in orthorhombic system and space symmetry group P212121 with the lattice parameters a = 0.9904 (5), b = 1.2477 (8), c = 1.6036 (17) nm. The crystal structure is composed of the binuclear units Ni2(H2O)5[(S,S)-EDDS] and molecules of crystal water. The anion [(S,S)-EDDS]4- coordinates to Ni(II) as a stereospecific hexadentate ligand, the six-membered β-alanine rings being situated in equatorial plane of the coordination polyhedron, the glycine rings being axial. Absolute configuration of the complex anion is (OC-6-13-A).

Crystal and molecular structure of carbonylcyanide-4-chlorophenylhydrazone(4-chlorophenylhydrazonopropanedinitrile)

1984 ◽  
Vol 49 (10) ◽  
pp. 2363-2370
Author(s):  
Viktor Vrábel ◽  
Ernest Šturdík ◽  
Michal Dunaj-Jurčo ◽  
Jan Lokaj ◽  
Ján Garaj
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Structural Analysis ◽  
Least Squares Method ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heavy Atom Method

The crystal structure of carbonylcyanide-4-chlorophenylhydrazone was solved by the single crystal X-ray diffraction method and interpreted by the heavy atom method. The compound crystallizes in the P21/c monoclinic group with 4 molecules per unit cell and with lattice parameters: a = 1.1843(3), b = 0.5944(1), c = 1.4922(3) nm and β = 117.92(2)°. The structure was refined by the least squares method for 1 078 observed reflections to a final value of R = 4.9%. The crystal structure consists of monomeric units, where hydrogen bonds were observed between atoms N3...H5 0.2193 nm and N3...H3 0.2404 nm between two molecules transformable through centre of symmetry -x, -y, -z. The name 4-chlorophenylhydrazonopropanedinitrile is recommended for the studied compound on the basis of this X-ray structural analysis.

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.

X-ray powder diffraction analysis of adducts triglycine fluoroberyllic acid and triglycine selenic acid for pyroelectric application

2001 ◽  
Vol 16 (3) ◽  
pp. 167-169 ◽  
Author(s):  
Yunxia Che ◽  
Jimin Zheng ◽  
Jianmin Hao ◽  
Lianqing Chu
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Analysis ◽  
Least Squares ◽  
Powder Diffraction ◽  
Structure Data ◽  
Crystal Structure Data ◽  
Least Squares Method ◽  
Lattice Parameters ◽  
X Ray

Two adducts (NH2CH2COOH)3⋅H2BeF4(TGFb) and (NH2CH2COOH)3⋅H2SeO4(TGSe) were obtained and characterized by X-ray powder diffraction. The samples were indexed using the TREOR program [Werner, Z. Kristallogr. Kristallogeom. Kristallphys. Kristallchem. 120, 375–387 (1964)] on a monoclinic unit cell. The lattice parameters of adducts TGFb and TGSe were refined by a least-squares method using the Lattice Constant Refinement Program of the Rikagu software. The refined lattice parameters are a=9.1589(9) Å, b=12.6204(13) Å, c=5.6966(8) Å, β=105.451(9)° for TGFb. The Smith and Snyder figure [Smith and Snyder, J. Appl. Crystallogr. 12, 60–65 (1979)] is F30=39.4(0.0141,54). The refined lattice parameters a=9.5063(11) Å, b=12.8281(10) Å, c=5.8682(7) Å, β=110.353(77)° for TGSe. The Smith and Snyder figure is F30=39(0.0106,73). The powder diffraction results are in agreement with those obtained from single crystal structure data.

Sign in / Sign up

Export Citation Format

Share Document