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

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.

1975 ◽  
Vol 53 (15) ◽  
pp. 2345-2350 ◽  
Author(s):  
Monique Authier-Martin ◽  
André L. Beauchamp

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.


1980 ◽  
Vol 33 (5) ◽  
pp. 979 ◽  
Author(s):  
W Choong ◽  
JF McConnell ◽  
NC Stephenson ◽  
JD Stevens

The crystal structure of the title compound was determined by X-ray diffraction and the use of the multi-solution programs MULTAN 74. Crystals are monoclinic, space group C2 with Z = 4 in a unit cell of dimensions: a 21.140(6), b 9.394(3), c 9.765(3) Ǻ, β 108.73(5)°. The structure was refined by full-matrix least-squares methods to a final R of 0.036 for 1858 diffractometer reflections. The seven-membered ring approximates to a twist-chair conformation very similar to that found for the gluco analogue.


1974 ◽  
Vol 27 (3) ◽  
pp. 503 ◽  
Author(s):  
LM Engelhardt ◽  
PWG Newman ◽  
CL Raston ◽  
AH White

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.


1974 ◽  
Vol 52 (12) ◽  
pp. 2197-2200 ◽  
Author(s):  
Peter L. Markila ◽  
James Trotter

Crystals of the title compound, N3P3Me6•I2, are triclinic, a = 10.707(13), b = 8.873(5), c = 8.871(6) Å, α = 96.65(6), β = 103.91(12), γ = 97.81(12)°, Z = 2, space group [Formula: see text] The structure was determined with MoKα diffractometer data by Patterson and Fourier syntheses, and was refined by full-matrix least-squares methods to R = 0.053 for 1934 observed reflexions. One atom of the iodine molecule is weakly bonded to nitrogen, N—I = 2.417(7), I—I = 2.823(1) Å, N—I—I = 177.8(2)°. The six-membered phosphazene ring is slightly non-planar, with a chair conformation. The two P—N bonds involving the nitrogen atom bonded to iodine are longer, mean 1.64 Å, than the other four P—N bonds, mean 1.598 Å Other mean dimensions are: P—C = 1.789 Å, N—P—N = 114.7, P—N—P = 124.0, C—P—C = 104°.


1978 ◽  
Vol 31 (5) ◽  
pp. 999 ◽  
Author(s):  
CL Raston ◽  
AH White ◽  
JK Yandell

The crystal structure of the title compound, NH4 [Co(NH3)4(SO3)2],3H2O, has been redetermined using diffractometer data at 295 K and refined by full-matrix least squares to a residual of 0.056 for 2068 'observed' reflections. Crystals are orthorhombic, P212121, a 10.978(4), b 17.552(7), c 6.828(3)Ǻ, Z 4. The redetermined structure provides accurate structural data for the cobalt environment; as well, it locates all hydrogen atoms and defines cations and water molecules un- ambiguously. Co-S are 2.224(2), 2.221(2) Ǻ. Co-N (trans to S) (1.993(6), 2.023(6) Ǻ) are longer than the mutually trans Co-N (1.970(7), 1.977(6) Ǻ); the difference in the former is a consequence of lattice hydrogen bonding.


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.


2004 ◽  
Vol 68 (5) ◽  
pp. 757-767 ◽  
Author(s):  
T. Mihajlović ◽  
H. Effenberger

AbstractHydrothermal synthesis produced the new compound SrCo2(AsO4)(AsO3OH)(OH)(H2O). The compound belongs to the tsumcorite group (natural and synthetic compounds with the general formula M(1)M(2)2(XO4)2(H2O,OH)2; M(1)1+,2+,3+ = Na, K, Rb, Ag, NH4, Ca, Pb, Bi, Tl; M(2)2+,3+ = Al, Mn3+, Fe3+, Co, Ni, Cu, Zn; and X5+,6+ = P, As, V, S, Se, Mo). It represents (1) the first Sr member, (2) the until now unknown [7]-coordination for the M(1) position, (3) the first proof of (partially) protonated arsenate groups in this group of compounds, and (4) a new structure variant.The crystal structure of the title compound was determined using single-crystal X-ray diffraction data. The compound is monoclinic, space group P21/a, with a = 9.139(2), b = 12.829(3), c = 7.522(2) Å, β = 114.33(3)°, V = 803.6(3) Å3, Z = 4 [wR2 = 0.065 for 3530 unique reflections]. The hydrogen atoms were located experimentally.


Author(s):  
H. M. Maurer ◽  
Alarich Weiss

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


2007 ◽  
Vol 63 (11) ◽  
pp. o4412-o4412 ◽  
Author(s):  
T. Augustine ◽  
V. Ramkumar ◽  
S. Arul Antony ◽  
Charles. C. Kanakam

In the crystal structure of the title compound, C31H25NO4, the five-membered heterocyclic ring is in an envelope conformation and the dihydropyrone ring is in a half-chair conformation.


1977 ◽  
Vol 30 (8) ◽  
pp. 1837 ◽  
Author(s):  
DPG Hamon ◽  
CL Raston ◽  
GF Taylor ◽  
JN Varghese ◽  
AH White

The crystal structure of the title compound, C12H18, has been determined at 295 K by X-ray diffraction and refined by full-matrix least squares to a residual of 0.049 for 216 ?observed? reflections; molecular geometry has been corrected for the effects of thermal motion using a rigid body approximation. Crystals are hexagonal, P63/m, a = 6.582(1), c = 11.843(3) Ǻ, Z = 2, the molecules occupying a hexagonal close- packed array.


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