Crystal and molecular structure of 4α-t-Butylcyclohexane-1β,2β-diol

1972 ◽  
Vol 25 (10) ◽  
pp. 2117 ◽  
Author(s):  
MD Brice ◽  
BR Penfold ◽  
WT Robinson

The crystal and molecular structure of 4α-t-butylcyclohexane-1β,2,β-diol, C10H20O2, has been determined by X-ray diffraction methods. The compound crystallizes in the triclinic space group Pi with 4 molecules in a unit cell of dimensions a = 12.268, b = 15.921, c = 6.322�, α = 82.53, β = 114.45, γ = 111.13�. The intensity data were measured by counter methods using Cu Kα radiation; the structure was solved by means of the tangent formula, and was refined using full matrix least-squares techniques to a final R-factor of 0.063 for 1199 reflections. The crystal structure consists of two sets of crystallographically non-equivalent molecules hydrogen-bonded to form discrete chains parallel to the c axis. The cyclohexane rings are in the chair conformation.

1979 ◽  
Vol 57 (2) ◽  
pp. 174-179 ◽  
Author(s):  
A. Wallace Cordes ◽  
Paul F. Schubert ◽  
Richard T. Oakley

The crystal structure of 1,4-diphenyl-2,2′,3,3′,5,5′,6,6′-octamethylcyclo-1,4-diphospha-2,3,5,6-tetrasilahexane, (PhPSi2Me4)2, has been determined by single crystal X-ray diffraction. The crystals are monoclinic, space group P21/c, with a = 9.866(1), b = 11.921(1), and c = 11.324(2) Å, β = 104.31(1)°, Z = 2, and ρcalcd = 1.15 g/cm3. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.060 and Rw of 0.078, for 1173 reflections with intensities greater than 3σ. The (PhPSi2Me4)2 molecule lies on a crystallographic centre of symmetry, and the six-membered P2Si4 ring has a chair conformation with equatorial phenyl groups. The endocyclic angles at P (104.4(1)°) and Si (104.9(2)°) are intermediate between those found in cyclic hexaphosphine and hexasilane molecules, and the Si—Si and P—Si distances of 2.345(3) and 2.252(4) Å, respectively, correspond to single bond lengths, with no appreciable evidence for secondary pπ → dπ bonding between phosphorus and silicon. The Si—C (1.867(8) Å) and P—C (1.828(7) Å) bond lengths are also normal. The variations in the Si—P—C (101.6(2)°, 108.6(2)°), P—Si—C (range 106.2(3)–120.0(3)°), and Si—Si—C (range 105.8(3)–113.7(3)°) angles indicate that the positions of the exocyclic methyl and phenyl groups are influenced by both intra- and intermolecular steric forces.


1983 ◽  
Vol 36 (6) ◽  
pp. 1249 ◽  
Author(s):  
TW Hambley ◽  
MR Snow

An X-ray crystallographic analysis of zinc(II) monoglycerolate has been carried out. The crystals are monoclinic, space group P21/c with a 8.110(1), b 6.404(1), c 8.714(2)� β 93.44(1)�. The structure was refined by full-matrix least-squares techniques to an R factor (on 519F) of 0.019. The analysis reveals that the zinc atoms bridge the glycerolate molecules forming polymeric sheets lying parallel to the bc plane. Only aliphatic hydrogens are disposed into the space between the layers, a fact consistent with the lubricity and hydrophobic nature of the solid complex and the observed facile lamellar cleavage perpendicular to the a axis.


1977 ◽  
Vol 55 (2) ◽  
pp. 333-339 ◽  
Author(s):  
Colin James Lyne Lock ◽  
Graham Turner

The crystal and molecular structure of the title compound has been examined by single crystal X-ray diffraction. The crystals are monoclinic with a = 28.045(10), b = 8.766(3), c = 12.376(5) Å, β = 91.14(3)°. The space group is C2/c and there are eight molecules per unit cell. A total of 5053 independent reflections, of which 2860 were observed, were examined on a Syntex [Formula: see text] diffractometer. The structure was refined by full matrix least squares to an R2 value of 0.0449. The ligands form a very rough octahedron around the rhenium atom with Re—Cl(1), 2.441(3); Re—Cl(2), 2.366(3), Re—O(1), 1.684(7); Re—O(2), 1.896(6); Re—N(1), 2.144(7); Re—N(2), 2.132(7) Å. The pyridine rings are a dominant factor in determining the details of the molecular structure.


1972 ◽  
Vol 50 (6) ◽  
pp. 912-916 ◽  
Author(s):  
P.-T. Cheng ◽  
S. C. Nyburg

The X-ray crystal structure analysis of the triphenyl–phosphine platinum ethylene complex (PPh3)2PtC2H4 is reported. The crystals belong to the monoclinic system a = 16.46(3), b = 10.85(2), c = 17.85(3) Å, β = 100.5(1)°, space group P21/a, Z = 4 molecules per cell.The ethylene C—C distance of 1.434(13) Å is in accord with that found when other transition elements form metallo-cyclopropanes. The structure has been refined by anisotropic full-matrix least-squares, the final R-factor being 0.043 for 4174 observed reflections.


1975 ◽  
Vol 53 (18) ◽  
pp. 2707-2713 ◽  
Author(s):  
Debbie Allen ◽  
Colin James Lyne Lock ◽  
Graham Turner ◽  
John Powell

The crystal and molecular structures of pentane-2,4-dionato-(2,3,5,6-tetrahapto-2,3-dicarbomethoxo[2.2.1]bicycloheptadienerhodium(I), Rh(C5H7O2)(C7H6(CO2CH3)2), have been measured by single crystal X-ray diffraction. The orange crystals are monoclinic, space group P21/c, Z = 4, a = 9.245(4), b = 9.003(4), c = 21.680(15) Å, β = 113.41(5)°. The calculated and observed densities are 1.645 and 1.642(5) respectively. Intensity data were collected on a Syntex [Formula: see text] diffractometer and a full matrix least squares refinement on 3010 observed reflections leads to a conventional R = 0.0660. The structure can be considered as a roughly square planar arrangement of ligands around the rhodium atom composed of two β-ketoenolate oxygen atoms (Rh—O, 2.037(5) and 2.025(5) Å ) and the centers of the two ethylenic groups. The Rh—C distances for the olefin group attached to the two carbomethoxo groups, 2.117(8), 2.108(8) Å, appear to be slightly larger than those for the other olefinic group, 2.087(7), 2.082(6), and the corresponding C=C distances of 1.375(10) and 1.410(9) Å are different at the 95% confidence level.


1985 ◽  
Vol 63 (3) ◽  
pp. 581-585 ◽  
Author(s):  
Kwong Khee Lai ◽  
Carl H. Schwalbe ◽  
Keith Vaughan ◽  
Ronald J. Lafrance ◽  
Clive D. Whiston

The crystal structures of the title compounds have been determined from X-ray data collected on a four-circle diffractometer and refined by the full-matrix least-squares method. The former compound crystallizes in the orthorhombic system, space group Pbcn, with a = 14.346(8), b = 7.239(1), c = 17.276(2) Å, and has been refined to a conventional R factor of 0.043 for 890 observed reflections. Corresponding results for the latter compound are monoclinic, P21/n, a = 12.222(4), b = 7.482(2), c = 14.170(8) Å, β = 94.06(4)°, R = 0.060 for 2128 observed data. The triazine rings of both compounds exhibit short N(1)—N(2) bonds and tetrahedral geometry at C(4); however, the ring is puckered in the first compound but flat in the second. Molecules in both crystals are linked by [Formula: see text] hydrogen bonds.


1997 ◽  
Vol 75 (5) ◽  
pp. 475-482 ◽  
Author(s):  
Wei Xu ◽  
Alan J. Lough ◽  
Robert H. Morris

New amineruthenium and amineiridium hydride derivatives have been synthesized and characterized with the objective of observing intramolecular [Formula: see text] or [Formula: see text] interactions. These include RuHCl(CO)(L)(PPri3)2 (1a, L = NH2NH2; 1b, L = NH3) and IrCl2(L)(H)(PCy3)2 (2a, L = SC(NH2)2; 2b, L = NH3; 2c, L = NH2NH2; 2d, L = NH2(CH2)3NH2; 2e, L = NH2OH). Instead, weak [Formula: see text] van der Waals contacts have been detected in the solid state by X-ray analysis and in solution by NMR T1 measurements and nOe techniques. Both X-ray crystal structure analysis and minimum T1 measurements indicate that the [Formula: see text] distances in the [Formula: see text] interactions are ca•2.0–2.2 Å. The weak interactions might influence the course of deuteration of these complexes under D2 gas. The crystal and molecular structure of IrCl2(NH3)(H)(PCy3)22a has been determined by X-ray diffraction at 173 K: monoclinic, space group P21/n, a = 14.859(2) Å, b = 18.579(3) Å, c = 18.548(3) Å, β = 97.29(1)°, V = 5079.1(13) Å3, Z = 4, full-matrix least-squares refinement on F2 for 10 953 independent reflections; R[F2 > 4σ(F2)] = 0.0283, wR(F2) = 0.0704. Keywords: ruthenium, iridium, hydride, dihydrogen, complexes, hydrogen bond, NMR, X-ray.


1986 ◽  
Vol 39 (4) ◽  
pp. 713 ◽  
Author(s):  
D Dakternieks ◽  
BF Hoskins ◽  
CL Rolls ◽  
ERT Tiekink

The crystal and molecular structure of bis ( tricyclohexylphosphine )cadmium(II) nitrate as its dichloromethane solvate, Cd [P(c-C6H11)3]2(NO3)2.CH2Cl2, has been determined by single- crystal, three-dimensional X-ray diffraction methods. The crystals of the cadmium(II) complex are monoclinic with space group C2/c, a 20.880(6), b 12.775(3), c 17.075(5) Ǻ and β 106.38(2)°, Z 4. The structure was solved by normal Fourier methods and refined by a full-matrix least-squares procedure. The refinement used the 2169 statistically independent reflections for which I ≥ 2σ(I) converged with R and Rw of 0.065 and 0.067 respectively. The crystals consist of discrete Cd [P(c-C6H11)3]2(NO3)2 molecules and CH2Cl2 in the ratio 1 : 1. There is a distorted tetrahedral environment around the cadmium atom formed from the coordination of the two phosphines and two nitrates with each nitrate essentially occupying one stereochemical position. The two markedly different Cd -O bond lengths of 2.405(9) and 2.575(8) Ǻ show gross asymmetry in the coordination of the nitrate.


1972 ◽  
Vol 50 (1) ◽  
pp. 93-98 ◽  
Author(s):  
F. W. B. Einstein ◽  
K. N. Slessor

The crystal and molecular structure of 3-chloro-3-deoxy-1,2;5,6-di-O-isopropylidene-β-D-idose has been determined from three dimensional X-ray data collected by counter methods. The structure was refined by full-matrix least-squares techniques to a conventional R factor of 5.7% for the 817 observed reflections. The compound crystallizes in the orthorhombic space group P212121 with four molecules in a cell of dimensions a = 9.744(6), b = 26.76(2), c = 5.403(3) Å.The structure analysis has served to confirm the site of halogenation and that it occurs stereospecifically. The conformation of the furan ring is an envelope arrangement with C(4) displaced from the mean plane.


1977 ◽  
Vol 30 (5) ◽  
pp. 1007 ◽  
Author(s):  
GR Scollary

A structural analysis of the platinum-silatrane complex, PtCl [Si(OCH2CH2)3N] [PMe2Ph]2, has been carried out by X-ray diffraction. Crystals are monoclinic, space group P21/c, a 6.630(4), b 17.465(6), c 22.297(6) Ǻ, β 97.4(2)�, Z 4. The structure has been refined by a full- matrix least-squares procedure to R 0.048 for 2165 reflections. Basic geometries are square (platinum), tetrahedral (silicon) and trigonal (nitrogen). Within the silatrane ligand, the Si-N non-bonding distance is 2.89(1) Ǻ.


Sign in / Sign up

Export Citation Format

Share Document