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.

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.

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.

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 Structure and Chirality of the Ansamycin Antibiotic Actamycin

1991 ◽  
Vol 44 (5) ◽  
pp. 655 ◽  
Author(s):  
TW Hambley ◽  
V Parthasarathi ◽  
RW Rickards ◽  
GB Robertson
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Double Bond ◽  
Least Squares ◽  
Absolute Configuration ◽  
Torsion Angle ◽  
Title Compound ◽  
Intermolecular Hydrogen Bonding ◽  
Triclinic Space Group ◽  
Relative Stereochemistry

The structure of the title compound has been determined from diffractometer data recorded, initially, at 294 K and, subsequently, at 168 K. Crystals are triclinic, space group P1 with (168 K values in square brackets) a 16.080(2) [15.934(2)], b 15.958(2) [15.880(2)], c 8.443(2)Ǻ [8.233(1)Ǻ], α 85.55(1) [86.04(1)],β 82.65(1) [82.56(1)],γ 85.00(1)° [84.73(1)°], and contain two actamycin and two solvent ( tetrahydrofuran ) molecules in the asymmetric scattering unit. The structure was solved with DIRDIF and refined by block-diagonal least-squares analysis (of 168 K data) to R 0.049 ( wR 0.069) for 5640 reflections and 940 refined parameters. Molecules of actamycin (30-dechloro-2-demethyl-30-hydroxynaphthomycin A) exhibit the same relative stereochemistry (8S*,9S*,15S*,18S*,19S*,20S*) and double-bond configuration (2Z,4Z,6E,12E,16E,21E) as reported for crystalline 25-O-methylnaphthomycin A iminomethyl ether but are quite differently conformed. The two crystallographically inequivalent actamycin molecules in the present structure also exhibit substantial conformational (torsion angle) differences due, apparently, to the effects of intermolecular hydrogen bonding. Consideration of chiroptical data defines the absolute configuration of actamycin as 8S,9S,15S,18S,19S,20S and the helicity as P, as in naphthomycin A.

Triaqua(2,2′-bipyridine)maleatonickel(II) monohydrate

2006 ◽  
Vol 62 (4) ◽  
pp. m865-m866 ◽  
Author(s):  
Mingtian Li ◽  
Xucheng Fu ◽  
Chenggang Wang
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Title Complex ◽  
Octahedral Coordination ◽  
Water Molecules ◽  
Hydrogen Bonding Interactions ◽  
Π Stacking

In the title complex, [Ni(C4H2O4)(C10H8N2)2(H2O)3]·H2O, the Ni atom has a distorted NiO4N2 octahedral coordination, formed by one maleate dianion, one bipyridine and three water molecules. The crystal structure is stabilized by π–π stacking and hydrogen-bonding interactions.

Synthesis and crystal structure of a 3D copper(II)–silver(I) coordination polymer assembled through hydrogen bonding, π–π stacking and metal–π interactions, {[Cu(phen)2(CN)][Ag(CN)2] · 3H2O}n (phen = 1,10-phenanthroline)

2015 ◽  
Vol 70 (7) ◽  
pp. 455-459 ◽  
Author(s):  
Sidra Nawaz ◽  
Tobias Rüffer ◽  
Heinrich Lang ◽  
Muhammad Ashraf Shaheen ◽  
Saeed Ahmad ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Coordination Polymer ◽  
Water Molecules ◽  
Monoclinic Space Group ◽  
Polymeric Complex ◽  
Synthesis And Crystal Structure ◽  
Space Group ◽  
Π Interactions ◽  
3D Network

AbstractA copper(II) polymeric complex {[Cu(phen)2(CN)][Ag(CN)2] · 3H2O}n, 1 (phen = 1,10-phenanthroline), has been prepared and structurally characterized. The compound crystallizes in the monoclinic space group P21/c with [Cu(phen)2(CN)]+ and [Ag(CN)2]− units and three water molecules. The cationic and anionic units are linked to each other through M-π and π–π interactions. The array is extended further by hydrogen bonding and π–π interactions to form a 3D network.

Crystal structure of diethylammonium tetrachloro(p-phenoxyphenyl)tellurate

1984 ◽  
Vol 62 (1) ◽  
pp. 32-35 ◽  
Author(s):  
Raj K. Chadha ◽  
John E. Drake ◽  
Masood A. Khan
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Heavy Atom ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Secondary Interaction ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Heavy Atom Method ◽  
Interionic Hydrogen

The crystal structure of diethylammonium tetrachloro(p-phenoxyphenyl)tellurate has been determined by the heavy atom method. The crystals are monoclinic, space group C2/c, with unit cell dimensions a = 19.675(5), b = 7.634(3), c = 28.716(6) Å, β = 105.58(2)°, and Z = 8. For 2636 "observed" reflections (I > 3σ(I)), R = 0.030. The primary geometry about tellurium is based on a square pyramid with a secondary interaction on the vacant side of the tellurium coordination octahedron. The ions are apparently linked by weak interionic hydrogen bonding along the crystallographic b axis.

A two-dimensional copper(I) polymer containing both molecular rod and anionic bridges: synthesis and crystal structure of (µ-chloro)-(µ-pyrazine)copper(I)

1995 ◽  
Vol 73 (10) ◽  
pp. 1591-1595 ◽  
Author(s):  
J.M. Moreno ◽  
J. Suarez-Varela ◽  
E. Colacio ◽  
J.C. Avila-Rosón ◽  
M.A. Hidalgo ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Heavy Atom ◽  
Electronic Spectroscopy ◽  
Chloride Ions ◽  
Monoclinic Space Group ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
Tetrahedral Environment ◽  
Heavy Atom Method

The crystal structure of bright-red crystals of the bidimensional polynuclear diamagnetic (µ-chloro)(µ-pyrazine)copper(I) complex has been analyzed from X-ray diffraction data. The structure was solved by the heavy-atom method. Full-matrix least-squares refinement based on 673 reflections with F > 4σ(F) converged to a final R = 0.043 and Rw = 0.048. Crystals of this complex are monoclinic, space group P2/c, a = 3.814(1), b = 6.356(1) and c = 11.497(5) Å; β = 96.04(2)°, Z = 2. The structure consists of planes of copper(I) atoms linked by pyrazine and Cl− bridges, each Cu(I) being in a distorted tetrahedral environment formed by two chloride ions and two nitrogen atoms belonging to two pyrazine molecules, with bond distances of Cu—Cl = 2.349(1) and Cu—N = 2.038(4) Å. Vibrational and electronic spectroscopy of the title compound is also reported. Keywords: two-dimensional copper(I)–pyrazine complexes.

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