Crystal and Molecular Structure of the s-fac-[Co((S)-Asp)(medien)]ClO4 . H2O . HClO4 Isomer

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.

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.


1989 ◽  
Vol 54 (12) ◽  
pp. 3220-3229
Author(s):  
Jan Ondráček ◽  
Jaroslav Maixner ◽  
Bohumil Kratochvíl ◽  
Jana Ondráčková ◽  
František Jursík

The crystal and molecular structure of unsym1-fac-Λ-(δ, chair)-(S)-[Co(aepn)(S)-Asp]ClO4(trans-6,6) was solved by the heavy atom method. The positions of the non-hydrogen atoms and their anisotropic temperature parameters were refined on the basis of 1 935 observed reflections, yielding values of R = 0.121 and wR = 0.117, affected by the undertermined position of the oxygen atoms in the ClO4-> anion. The substance crystallizes in the orthorhombic system with space group P212121; Z = 4, a = 9.664(1), b = 11.805(1), c = 13.966(2) Å. The secondary atom of the triamine has S configuration, the conformation of the five-membered chelate ring approaches that of the asymmetrical δ envelope and the six-membered ring has chair configuration. Both conformations are deformed. The donor atoms deviate from the defined planes and thus form further sources of chirality (λ) contributing to the optical activity of the isomer. These deviations lead to the similarity of the CD spectra of the isomers.


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.


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.


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.


1978 ◽  
Vol 33 (3) ◽  
pp. 316-320 ◽  
Author(s):  
Werner Winter ◽  
Udo Plücken ◽  
Herbert Meier

Abstract A final decision between the 2-and 3-oxide structure of the thermally or photo-chemically accessible monoxides of 1,2,3-thiadiazoles is given with the aid of an X-ray analysis of 4-phenyl-1,2,3-thiadiazole-3-oxide. The compound crystallizes in the ortho-rhombic space group Pbca, Z = 8, with a = 7.598(6), b= 18.865(5) and c= 11.225(6) Å. The structure was solved by the heavy atom method and refined to R = 0.042 for 1643 independent reflections. The heterocyclic ring is planar within experimental error and the bond distances S-C and S-N are rather short. In the crystal the molecules are linked by an unusual short contact distance between sulphur and oxygen (2.75 Å).


1984 ◽  
Vol 62 (9) ◽  
pp. 1662-1665 ◽  
Author(s):  
Masood A. Khan ◽  
Clovis Peppe ◽  
Dennis G. Tuck

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.


1983 ◽  
Vol 61 (12) ◽  
pp. 2809-2812 ◽  
Author(s):  
P. Michael Boorman ◽  
Joanne M. Ball ◽  
Kelly J. Moynihan ◽  
Vikram D. Patel ◽  
John F. Richardson

The complex (Me2S)Cl3W(μ-SPh)2WCl3(SMe2), 1, has been isolated as one product of the 1:1 reaction between WCl4(Me2S)2 and SiMe3(SPh) in CH2Cl2 solution. A single crystal X-ray diffraction study shows that the molecule has the relatively unusual edge-shared bioctahedral structure, with a W—W bond length of 2.759(1) Å. The dimethyl sulfide ligands occupy positions trans to one another in the equatorial mean plane of the molecule, which has two-fold symmetry imposed on it. The structure was solved by the heavy atom method and refined to R = 0.044 and Rw = 0.058 for 2001 reflections. Crystals of 1 are monoclinic, space group C2/c, with a = 17.445(4), b = 12.594(2), c = 11.509(3) Å, β = 91.22(1)°, and Z = 4.


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