The crystal and molecular structure of calcium (S,S)-ethylenediamine-N,N'-disuccinatoferrate octahydrate

1983 ◽  
Vol 48 (5) ◽  
pp. 1376-1389 ◽  
Author(s):  
František Pavelčík ◽  
Viktor Kettmann

Crystals of Ca[Fe((S,S)-EDDS)]2.8 H2O are monoclinic with lattice parameters of a = 1.0284, b = 0.8403, c = 2.1273 nm, β = 116.04°. The space group is Pc, Z = 2. The structure was solved by the heavy atom method and refined by the least squares method to give R = 0.057. The crystals consist of [Fe(III) ((S,S)-EDDS)]- anions, hydrated Ca2+ cations and molecules of water of crystallization. The iron atoms are coordinated by two nitrogen atoms and four oxygen atom of the carboxyl groups of the hexadentate ligand. The coordination polyhedron of the iron atom forms a deformed octahedron. The absolute configuration of the complex is (O,C-6-13-A) for the (S,S) absolute ligand configuration.

1980 ◽  
Vol 45 (6) ◽  
pp. 1766-1774 ◽  
Author(s):  
František Pavelčík ◽  
Jiřina Soldánová ◽  
Jaroslav Majer

Crystals of Co3((R,S)-EDDS)2 . 14 H2O are monoclinic with lattice parameters a = 1.1393, b = 1.1856, c = 1.5267 nm, β = 114.6°. The space group is P21/c, Z = 2. The structure was solved by the heavy atom method and refined by the least squares method to R = 0.082. The crystals are composed of binuclear [CO2((R,S-EDDS)2]2- anions, [CO(OH2)6]2+ cations and crystal water molecules. The cobalt atom in [Co2((R,S)-EDDS)2]2- is coordinated octahedrally by two nitrogen atoms and three oxygen atoms from different carboxyl groups in a single [(R,S)-EDDS]4- molecule and one oxygen atom from a neighbouring [(R,S)-EDDS]4- molecule. The [Co(OH2)6]2+ cation is coordinated octahedrally.


1979 ◽  
Vol 44 (4) ◽  
pp. 1070-1079 ◽  
Author(s):  
František Pavelčík ◽  
Viktor Kettmann ◽  
Jaroslav Majer

[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).


1984 ◽  
Vol 49 (10) ◽  
pp. 2363-2370
Author(s):  
Viktor Vrábel ◽  
Ernest Šturdík ◽  
Michal Dunaj-Jurčo ◽  
Jan Lokaj ◽  
Ján Garaj

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.


1994 ◽  
Vol 59 (5) ◽  
pp. 1052-1058 ◽  
Author(s):  
Jan Ondráček ◽  
Jana Ondráčková ◽  
Jaroslav Maixner ◽  
František Jursík

The crystal and molecular structure of s-fac-[Co((S)-Asp)(dien)]ClO4 . HClO4 .2 H2O (dien = 1,4,7-triazaheptane) was solved by the heavy atom method. The position parameters of the non-hydrogen atoms and their anisotropic temperature parameters were refined based on 1 726 observed reflections with a final value of R = 0.073. The substance crystallizes in the orthorhombic system in the space group P212121, Z = 4, a = 8.506(1), b = 17.171(2), c = 13.277(1) Å. The structure involves hydrogen bonds between the O2, O4 and HN2 atoms of aspartic acid and the two molecules of water. The five-membered dien chelate rings take the asymmetric envelope conformations. The five-membered ring of (S)-aspartic acid possesses the symmetric envelope conformation whereas the six-membered ring exhibits the skew boat conformation.


1990 ◽  
Vol 55 (4) ◽  
pp. 1010-1014 ◽  
Author(s):  
Jiří Kameníček ◽  
Richard Pastorek ◽  
František Březina ◽  
Bohumil Kratochvíl ◽  
Zdeněk Trávníček

The crystal and molecular structure of the title compound (C8H16N2NiS4) was solved by the heavy atom method and the structure was refined anisotropically to a final R factor of R = 0.029 (wR = 0.037) for 715 observed reflections. The crystal is monoclinic, space group P21/c with a = 948.3(2), b = 776.9(2), c = 1 167.4(2) pm, β = 125.14(2)°, Z = 2. The molecule contains two four-membered NiSCS rings of approximately planar configuration with the Ni atom situated at a centre of symmetry. The molecules are arranged in chains along the c-axis of the unit cell.


1984 ◽  
Vol 62 (3) ◽  
pp. 601-605 ◽  
Author(s):  
Masood A. Khan ◽  
Clovis Peppe ◽  
Dennis G. Tuck

The crystal structure of the title compound has been determined by the heavy atom method. The crystals are orthorhombic, space group Pbca, with unit cell dimensions a = 22.795(3) Å, b = 17.518(2) Å, c = 12.396(3) Å, Z = 8; R = 0.0409 for 1527 unique "observed" reflections. The structure is disordered, with each halogen site (X) occupied by 75% Br, 25% I. The molecule consists of two X2(tmen)In units (tmen = N,N,N′,N′-tetramethylethanediamine) with distorted trigonal bipyramidal geometry, joined by an In—In bond 2.775(2) Å in length.


1975 ◽  
Vol 53 (22) ◽  
pp. 3383-3387 ◽  
Author(s):  
Joseph Hubert ◽  
André L. Beauchamp ◽  
Roland Rivest

The crystal and molecular structure of dithiocyanato(triphenylarsine)mercury(II) has been determined from X-ray diffraction data. The crystals are monoclinic, space group P21/c, with a = 10.290(7), b = 21.199(23), c = 10.719(7) Å, β = 112.00(2)°, and Z = 4. The structure has been solved by the heavy-atom method and refined by block-diagonal least-squares calculations. The agreement factor R obtained for 2607 'observed' reflections is 0.030. The crystal consists of single molecules. The 'characteristic' coordination number of mercury is three, with two sulfur and one arsenic atoms at the apexes of a triangle. The nitrogen atoms of the thiocyanate groups are at 2.67 and 2.74 Å from the adjoining mercury atoms and therefore link the different molecules together.


1983 ◽  
Vol 48 (10) ◽  
pp. 2893-2902 ◽  
Author(s):  
Viktor Vrábel ◽  
Jan Lokaj ◽  
Ján Garaj

The crystal structure of [Cu(en)2](SeCN)2 was solved by the heavy atom method and refined by the least squares method using the full matrix and anisotropic thermal parameters to a value of R = 0.063 for 660 observed reflections. The crystals are triclinic , with a space group of P1 and lattice parameters of a = 6.660(2), b = 9.360(2), c = 7.754(2) . 10-10 m, α = 129.22(2), β = 109.87(2) and γ = 92.38(2)°, Z = 1. The structure consists of discrete molecules that are centrosymmetric. The Cu(II) atom occupies a special position at the centre of symmetry and is coordinated by 4 nitrogen atoms from two bidentate ethylenediamine molecules: C-N 1.999(8) and 2.033(8) . 10-10 m and angle N1-Cu-N2, 84.1(3)°. The selenium atom in the SeCN group completes this square planar arrangement to form a deformed octahedron along the longer Cu...Se distance of 3.263(2) . 10-10 m. The ethylenediamine molecule has a non-symmetrical gauche arrangement with the carbon atoms C1 and C2 + 0.542 and -0.095 . 10-10 m above and below the N1-Cu-N2 coordination plane, respectively.


1993 ◽  
Vol 58 (2) ◽  
pp. 335-342 ◽  
Author(s):  
Jan Ondráček ◽  
Jaroslav Maixner ◽  
Jana Ondráčková ◽  
František Jursík

The crystal and molecular structure of s-fac-[Co((S)-Asp)(medien)]ClO4 . H2O . HClO4 was elucidated by the heavy atom method. The positional parameters of the nonhydrogen atoms and their anisotropic temperature parameters were refined based on 2 474 observed reflection with final values of R = 0.0603 and wR = 0.0616. The substance crystallized in the orthorhombic system in the space group P212121, Z = 4, a = 8.536(1), b = 13.378(1), c = 16.899(2) Å. The structure comprises layers of the complex cation which alternate with layers containing two perchlorate anions and one hydroxonium cation. The five-membered chelate ring of 4-methyl-1,4,7-triazaheptane exist in the asymmetric λ, δ envelope conformations and the N-CH3 group of the triamine has the exo orientation. The five-membered ring of (S)-aspartic acid assumes the symmetric envelope conformation, the six-membered chelate ring, the skew boat conformation.


1970 ◽  
Vol 48 (2) ◽  
pp. 307-311 ◽  
Author(s):  
H. Lynton

The molecular structure of the m-bromobenzoate derivative of bisnorquassin, C27H27O7Br, has been determined by the heavy atom method. The compound crystallizes in the orthorhombic system, space group P212121, with unit cell dimensions a = 20.09 ± 0.02 Å, b = 14.63 ± 0.02 Å, c = 8.06 + 0.01 Å and 4 molecules in the unit cell. Final atomic parameters have been obtained from a blockdiagonal least-squares refinement using anisotropic temperature parameters. The final agreement residual for 1665 observed reflections is R = 0.107.The structure of bisnorquassin previously proposed by Findlay and Cropp, on the basis of spectroscopic and chemical evidence, is shown to be essentially correct.


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