The Crystal and Molecular Structure of Penta-P-tolylantimony, (p-CH3C6H4)5Sb

1973 ◽  
Vol 51 (17) ◽  
pp. 2952-2957 ◽  
Author(s):  
C. Brabant ◽  
J. Hubert ◽  
A. L. Beauchamp
Keyword(s):  
Molecular Structure ◽  
Solid State ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
The Other ◽  
Monoclinic Space Group ◽  
R Factor ◽  
Equatorial Bond ◽  
Derivatives Of ◽  
Heavy Atom Method

Penta-p-tolylantimony crystals are monoclinic, space group P21/c, with a = 14.545(5), b = 4(6), c = 19.754(8) Å, β = 122.88(4)°, and Z = 4. The structure was solved by the standard heavy-atom method and anisotropic refinement on 1677 independent observed reflections led to a conventional R factor of 0.051. Unlike pentaphenylantimony, which is known to exist as square pyramidal molecules in the crystal, the corresponding penta-p-tolyl derivative exhibits the more common trigonal bipyramid structure. The Sb—C equatorial bond length average, 2.16 Å, is significantly shorter than the axial average, 2.26 Å. Two of the C—Sb—C bond angles in the equatorial plane (113, 130°) differ considerably from 120°, but the other angles around antimony are normal. Packing forces appear to play a determining role in the structures observed for penta-aryl derivatives of antimony in the solid state.

Determination of the structure of bis(propyldithiocarbamate)nickel(II)

1990 ◽  
Vol 55 (4) ◽  
pp. 1010-1014 ◽  
Author(s):  
Jiří Kameníček ◽  
Richard Pastorek ◽  
František Březina ◽  
Bohumil Kratochvíl ◽  
Zdeněk Trávníček
Keyword(s):  
Molecular Structure ◽  
Title Compound ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Planar Configuration ◽  
Compound C ◽  
Heavy Atom Method

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.

Crystal and Molecular Structure of Dithiocyanato(triphenylarsine)mercury(II)

1975 ◽  
Vol 53 (22) ◽  
pp. 3383-3387 ◽  
Author(s):  
Joseph Hubert ◽  
André L. Beauchamp ◽  
Roland Rivest
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Coordination Number ◽  
Diffraction Data ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heavy Atom Method

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.

The crystal and molecular structure of di-μ-phenylthiolatobis[trichloro(dimethyl sulfide) tungsten(IV) (W—W)]

1983 ◽  
Vol 61 (12) ◽  
pp. 2809-2812 ◽  
Author(s):  
P. Michael Boorman ◽  
Joanne M. Ball ◽  
Kelly J. Moynihan ◽  
Vikram D. Patel ◽  
John F. Richardson
Keyword(s):  
Molecular Structure ◽  
Bond Length ◽  
Dimethyl Sulfide ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sulfide Ligands ◽  
Heavy Atom Method

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.

The Crystal and Molecular Structure of sym-fac-(1,4,7-Triazaheptane)-(S)-aspartatocobalt(III) Diperchlorate Dihydrate

1994 ◽  
Vol 59 (5) ◽  
pp. 1052-1058 ◽  
Author(s):  
Jan Ondráček ◽  
Jana Ondráčková ◽  
Jaroslav Maixner ◽  
František Jursík
Keyword(s):  
Molecular Structure ◽  
Aspartic Acid ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Membered Ring ◽  
Boat Conformation ◽  
Hydrogen Atoms ◽  
Orthorhombic System ◽  
Anisotropic Temperature ◽  
Heavy Atom Method

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.

scholarly journals The crystal and molecular structure of the bis(N,N,N′,N′-tetramethylethanediamine) adduct of I(Br)InInBr2, In2Br3I•2C6H16N2, an indium–indium bonded molecule

1984 ◽  
Vol 62 (3) ◽  
pp. 601-605 ◽  
Author(s):  
Masood A. Khan ◽  
Clovis Peppe ◽  
Dennis G. Tuck
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Orthorhombic Space Group ◽  
Trigonal Bipyramidal ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Heavy Atom Method ◽  
Distorted Trigonal Bipyramidal

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.

The Crystal and Molecular Structure of Dinitrato(triphenylphosphine)mercury(II)

1974 ◽  
Vol 52 (2) ◽  
pp. 198-202 ◽  
Author(s):  
Simon H. Whitlow
Keyword(s):  
Molecular Structure ◽  
Single Crystal ◽  
Crystal And Molecular Structure ◽  
Bond Distance ◽  
The Other ◽  
Tetrahedral Coordination ◽  
X Ray ◽  
R Factor ◽  
Computer Controlled ◽  
Distorted Tetrahedral Coordination

The structure of dinitrato(triphenylphosphine)mercury(II), Hg(N03)2.P(C6H5)3, has been determined from single–crystal X-ray data measured on a computer–controlled diffractometer. The crystals are monoclinic, have a unit cell of dimensions a = 10.39(1), b = 9.56(1), c = 19.44(2) Å, β = 94.3(1)°, which contains 4 molecules, and they belong to the space group, P21/c. The structure has been refined by least–squares methods from 2470 independent observed reflections to a conventional R-factor of 0.061. The Hg atom has a distorted tetrahedral coordination with Hg—O bond lengths of 2.190(8), 2.428(8), and 2.560(9) Å and an Hg—P bond distance of 2.359(3) Å. There are 2 distinct types of NO3 groups bonded to Hg. One is an unshared, unidentate ligand and the other acts as a bridging group joining 2 Hg atoms. Chains of—Hg—NO3—Hg—atoms are formed which follow crystallographic two-fold screw axes in the b-direction.

The crystal and molecular structure of streptomycin oxime selenate tetrahydrate

1978 ◽  
Vol 359 (1698) ◽  
pp. 365-388 ◽  
Keyword(s):  
Molecular Structure ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Water Molecules ◽  
Monoclinic Space Group ◽  
Hydrogen Atoms ◽  
Glycosidic Bonds ◽  
Compound C ◽  
Cell Dimensions ◽  
Network Of Hydrogen Bonds

The crystal and molecular structure and absolute configuration of the antibiotic streptomycin have been determined by an X-ray study of the hydrated oxime selenate. The compound (C 21 H 40 N 8 O 12 . 1 1/2 H 2 SeO 4 .4H 2 O) crystallizes in the monoclinic space group C 2, with cell dimensions a = 17.10(1), b = 14.36(1), c = 16.13(1)Å∥, β = 108.0(2)°; Z = 4 The structure was solved by the heavy-atom method, by using 3236 visually-estimated intensities, and refined to a conventional R of 0.086. The analysis has confirmed that streptomycin consists of three fragments, an N -methyl- α-L-glucosamine ring, an α-L-streptose and a streptidine ring, linked together by two glycosidic bonds. The crystal structure contains an elaborate network of hydrogen bonds linking selenate and streptomycin oxime ions and water molecules, analysis of which, though somewhat hampered by inability to observe the hydrogen atoms experimentally, reveals a disordered hydrogen bond occurring between two diad-related water molecules.

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
Keyword(s):  
Molecular Structure ◽  
Crystal And Molecular Structure ◽  
Chelate Ring ◽  
Complex Cation ◽  
Heavy Atom ◽  
Boat Conformation ◽  
Membered Chelate Ring ◽  
Anisotropic Temperature ◽  
Hydroxonium Cation ◽  
Heavy Atom Method

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.

Crystal and molecular structure of the m-bromobenzoate derivative of bisnorquassin

1970 ◽  
Vol 48 (2) ◽  
pp. 307-311 ◽  
Author(s):  
H. Lynton
Keyword(s):  
Molecular Structure ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Unit Cell ◽  
Anisotropic Temperature ◽  
Cell Dimensions ◽  
Final Agreement ◽  
Unit Cell Dimensions ◽  
Heavy Atom Method ◽  
Atomic Parameters

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.

The structural features of a tetrahedral 1,3-monothiolate complex: The crystal and molecular structure of Bis(ethyl 3-mercaptobut-2-enoato)zinc(II)

1977 ◽  
Vol 30 (5) ◽  
pp. 993 ◽  
Author(s):  
BF Hoskins ◽  
CD Pannan
Keyword(s):  
Molecular Structure ◽  
Least Squares Method ◽  
Crystal And Molecular Structure ◽  
Lone Pair ◽  
Structural Features ◽  
The Other ◽  
Zinc Atom ◽  
Monoclinic Space Group ◽  
Hydrogen Atoms ◽  
Mean Values

The crystal and molecular structure of bis(ethy 3-mercaptobut-2- enoato)zinc(II) has been determined by single-crystal X-ray diffraction techniques. Solved by conventional Patterson and Fourier methods the structure was refined by a least-squares method employing anisotropic thermal parameters to all non-hydrogen atoms to R and Rw values of 0.040 and 0.046 respectively. The complex crystallizes in the monoclinic space group P21/c with four molecules in a unit cell of dimensions a 11.107(1), b 18.239(2) and c 8.438(1) Ǻ and β 107.7(1)�. The intensities of 2274 independent and statistically significant [I ≥ 3σ(I)] reflections with θ values ≤ 70� were measured by counter methods using nickel- filtered Cu Kα radiation. The crystals comprise discrete monomeric molecules with the zinc atom bonded to two sulphur atoms and two oxygen atoms giving a coordination arrangement which is substantially distorted from an ideal tetrahedron. The mean values for the Zn-S and Zn-O bond distances are 2.247(1) and 2.007(3) Ǻ respectively and the average S-Zn-O intraligand bond angle is 99.25(8)�. The geometries of the ligands differ in two ways. Firstly, the two ethyl groups adopt differing conformations and secondly, while one ligand moiety is essentially planar with the zinc atom displaced about 0.1 Ǻ from that plane, the displaced atom in the other ligand is the carbon bonded to the sulphur atom and not the metal which is, in this instance, coplanar with the other members of the ring. Bond distances in each chelate ring indicate aromatic character with a lone pair of electrons on the ethoxy-oxygen participating in the delocalization.

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