The crystal and molecular structure of syn-2,11-dithia[3,3]metacyclophane

1979 ◽  
Vol 57 (23) ◽  
pp. 3080-3087 ◽  
Author(s):  
Willem Anker ◽  
Gordon W. Bushnell ◽  
Reginald H. Mitchell
Keyword(s):  
Crystal And Molecular Structure ◽  
Fold Axis ◽  
X Ray Diffraction ◽  
Aromatic Rings ◽  
X Ray ◽  
Anti Conformer ◽  
Cell Dimensions ◽  
Out Of Plane ◽  
Methylene Groups ◽  
Axis Of Symmetry

The crystal structure of syn-2,11-dithia[3,3]metacyclophane, C16H16S2, has been determined by single crystal X-ray diffraction and refined to an R-value of 0.049. The crystal is monoclinic with cell dimensions a = 1898.2(5), b = 795.7(3), c = 924.1(4) pm, β = 100.03°(4). The space group is P21/n with 4 molecules per cell, Dm = 1.34 g cm−3, Dc = 1.317 g cm−3. Of several possible syn conformations, the molecule is found in that with the largest S—S distance of 697.4 pm. The benzenoid rings form a dihedral angle of 20.6°. The distance between the pair of aromatic H atoms which are ortho to two methylene groups is 273.0 pm, with 305.2 pm between the carbon atoms to which they are attached. Small angular distortions are observed at these carbon atoms. Mean bond lengths are: C—S 181.0(12), C—C (aromatic) 138.5(8), C—C (bridge) 151.0(11) pm. Mean bond angles are: C—S—C 104°(1), S—C—C 115.4°(9). The C—C—C angles are in the range 117.9–122.7°. The molecule possesses an approximate (non-crystallographic) 2-fold axis of symmetry passing through the midpoints of C(8)—C(18) and C(4)—C(14). The aromatic rings are planar, with the methylene carbons 5–11 pm out of plane on the sulphur side. The S(1) is 171.8(2) pm from plane 1 and 136.8(2) pm from plane 2, while for S(2) the corresponding values are 136.0(2) and 175.3(2) respectively.1Hmr data have been re-examined and compared with those obtained for other cyclophanes, together with 13Cmr data and are consistent with the fact that in solution 2,11-dithia[3,3]metacyclophane, 1, exists as the syn-conformer with no appreciable participation of the anti-conformer. All related dithia[3,3]metacyclophanes which have internal aryl hydrogens (i.e., no internal substituents) likewise appear to be syn from 1Hmr data.

Structural study in the oligomethylene dithiobenzoate series, nDBS, where n, the number of methylene groups, is odd

1992 ◽  
Vol 70 (3) ◽  
pp. 900-909 ◽  
Author(s):  
Claude Leblanc ◽  
François Brisse
Keyword(s):  
Crystal Structure ◽  
X Ray Diffraction ◽  
Aromatic Rings ◽  
Monoclinic System ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cells ◽  
Methylene Groups ◽  
Unit Cell Dimensions ◽  
Centrosymmetric Dimers

Model compounds of the poly(oligomethylene thioterephthalates) have been synthesized and characterized by X-ray diffraction analyses. The pink n-methylenedithiobenzoates, obtained for n = 3, 5, 7, and 9, all have a low melting point of about 320–330 K. They all crystallize in the monoclinic system, space group P21/c. The a and b unit cell dimensions vary little while the c dimension increases monotonically as n changes from 3 to 9. The crystal structure of the four compounds were established from low-temperature X-ray intensities. Except for the lengthening of the methylenic sequence, the four molecules studied here are isostructural. One of the thiobenzoate groups of the molecules is coplanar with all the methylenic carbons, while the other thiobenzoate group is at 90° from the above plane of atoms. The methylenic sequence has the same conformation. It may be described by g+(t)n, where n is the number of methylene groups. Thus, the four compounds belong to a crystallographically homologous series. The molecules form centrosymmetric "dimers," which, in turn, are herring-bone packed in their respective unit cells. In each "dimmer" two aromatic rings are across from one another while being mutually perpendicular. On the basis of the above results, one proposes three potentially acceptable structures for the parent poly(oligomethylene thioterephthalates). Keywords: dithiobenzoate, methylene sequence, crystal structure, poly(oligomethylene thioterephthalate).

Crystal structures of medium ring compounds. Part II. The crystal and molecular structure of cis-anti-cis-4,5:9,10-biscyclohexano-1,3,6,8-tetraoxecane

1978 ◽  
Vol 56 (12) ◽  
pp. 1705-1709 ◽  
Author(s):  
Aris Terzis ◽  
J. Brian Faught ◽  
T. Bruce Grindley
Keyword(s):  
Crystal And Molecular Structure ◽  
Boat Conformation ◽  
X Ray Diffraction ◽  
Stable Conformation ◽  
Relative Configuration ◽  
X Ray ◽  
Ring Compounds ◽  
Methylene Groups ◽  
R Value ◽  
Medium Ring

The crystal structure of cis-anti-cis-4,5:9,10-biscyclohexano-1,3,6,8-tetraoxecane (2) has been determined by X-ray diffraction. The crystals are monoclinic, a = 11.120(1), b = 8.127(1), c = 7.990(1) Å, β = 110.01(1)°, P21/c, with Z = 2. The structure was solved by the application of symbolic addition procedures and refined to a final R value of 0.031 (Rw 0.040) for 989 reflections with I > 2.0σ(I).This structural determination confirms a previous tentative assignment of the relative configuration of 2. In the crystal, the two cis-substituted cyclohexane rings adopt chair conformations in which the equatorial oxygens on different rings are linked through methylene groups to axial oxygens on the other rings. The central 10-membered tetraoxecane ring adopts the boat–chair–boat conformation, the most stable conformation for cyclodecane.

The crystal and molecular structure of syn-9-phenyl-2,11-dithia[3,3]metacyclophane

1984 ◽  
Vol 62 (4) ◽  
pp. 661-666 ◽  
Author(s):  
Willem Anker ◽  
Kathy A. Beveridge ◽  
Gordon W. Bushnell ◽  
Reginald H. Mitchell
Keyword(s):  
Crystal Structure ◽  
Crystal And Molecular Structure ◽  
Variable Temperature ◽  
Phenyl Group ◽  
Outer Side ◽  
X Ray Diffraction ◽  
X Ray ◽  
Out Of Plane ◽  
Boat Form ◽  
The Mean

The crystal structure of syn-9-phenyl-2,11-dithia[3,3]metacyclophane, 6, has been determined by single crystal X-ray diffraction and refined to an R value of 0.0723. The crystal structure is triclinic with a = 9.573(2), b = 12.010(4), c = 8.433(2) Å, α = 108.02(2)°, β = 95.95(2)°, γ = 102.25(3)°, and the space group is [Formula: see text] with two molecules per cell, D(meas) = 1.313 g cm−3, D(calc) = 1.306 g cm−3. The bridging S atoms differ in their conformations so that the S … S distance is 6.391 Å. The metacyclophane rings have a distance of 3.57 Å between their centres and form a dihedral angle of 20.5°. The phenyl substituent forms an angle of 78.6° with the adjacent ring and has an ortho H-atom very close to the internal H-atom of the opposite ring. The phenyl substituted aromatic ring is non-planar and in a shallow boat form, the ring atoms C(11) (internal) and C(14) being 0.038(4) and 0.037(5) Å out-of-plane on the outside, the methylene C substituents are 0.212(5) and 0.199(5) Å out-of-plane on the inside. The first atom of the phenyl group is in the bowsprit position and is 0.274(4) Å above the mean plane on the outer side of the molecule. The opposite metacyclophane ring is less strained but in a similar boat form with the methylene C-atoms 0.092(4) and 0.067(6) Å to the inside. The mean bond angle at S is 103.5(2)°, the angles at C (methylene) range from 113.3(3)° to 118.0(3)°.The variable temperature 1Hmr spectra results are consistent with the syn conformer 6 being dominant in solution and frozen at temperatures <60 °C as conformer A, with only relatively restricted further twisting of the biphenyl being found at ambient temperature.

scholarly journals The Crystal and Molecular Structure of Diazido-2,2′-bipyridinecopper(II)

1974 ◽  
Vol 52 (17) ◽  
pp. 3125-3133 ◽  
Author(s):  
Gordon W. Bushnell ◽  
Masood A. Khan
Keyword(s):  
Molecular Structure ◽  
Crystal And Molecular Structure ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Lengths ◽  
Square Planar ◽  
Copper Coordination ◽  
Cell Dimensions ◽  
Coordinate Bond

The crystal and molecular structure of diazido-2,2′-bipyridinecopper(II), C10H8N2(N3)2Cu, is determined by single crystal X-ray diffraction, and refined to an R value of 0.067. The cell dimensions are a = 664.9(2), b = 843.3(1), c = 1082.0(2) pm, α = 86.99(2)°, β = 87.77(3)°, γ = 78.59(2)°. The space group is [Formula: see text] (No. 2) with 2 molecules per unit cell and the measured density is 1.71(2) g cm−3. The copper coordination is square planar with two additional longer bonds. The coordinate bond lengths in pm to the bipyridine ligand are: Cu—N(1), 201.6(6); Cu—N(2), 201.9(6). The coordinate bonds to the azido ligands are: Cu—N(3), 194.9(6); Cu—N(6), 196.6(6). The longer bonds are: Cu—N(3)″, 268.0(8), Cu—N(6)′ 268.2(8). The N—N bond lengths within each azido ligand are unequal: N(3)—N(4), 118.2(10); N(4)—N(5), 115.4(11); N(6)—N(7), 119.2(9); N(7)—N(8), 114.8(9). The angles at N(3) and N(6) are both 130° and at N(4) and N(7) the angles are both 175(1)°. Each azide takes part in asymmetric bridging through a single nitrogen atom. The results are compared with other structural studies on azido complexes and to a nitrate complex of Ag(II) which is structurally similar.

Molekül-und Kristallstruktur des 5.5' -Diethoxycarbonyl-3.3' -diethyl-4.4' -dimethyl-pyrromethen-hydrobromids / Crystal and Molecular Structure of 5,5'-Diethoxycarbonyl-3,3'-diethyl-4,4'-dimethyl-pyirromethene Hydrobromide

1978 ◽  
Vol 33 (7) ◽  
pp. 753-755 ◽  
Author(s):  
G. Struckmeier ◽  
J. Engel ◽  
U. Thewalt
Keyword(s):  
Molecular Structure ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Crystal And Molecular Structure ◽  
Ion Pairs ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Dimensions

Abstract The crystal and molecular structure of the title compound has been determined by X-ray diffraction. The compound possesses an (almost) planar Z configuration. The ions form ion pairs in the solid state: each bromide anion is connected via two hydrogen bonds with a cation. The crystal data are: space group P21/n with Z = 4; cell dimensions a = 14.097(2), b = 11.591(2), c = 14.133(3) Å, β = 106,22(2)°.

The crystal and molecular structure of syn-2,11-diselena[3,3]metacyclophane and comparison with the dithia-analogue

1982 ◽  
Vol 60 (3) ◽  
pp. 362-367 ◽  
Author(s):  
Gordon W. Bushnell ◽  
Reginald H. Mitchell
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Solid State ◽  
Crystal And Molecular Structure ◽  
State Structure ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
X Ray ◽  
Anti Conformer ◽  
R Value

The crystal structure of syn-2,11-diselena[3,3]metacyclophane, 1a, has been determined by single crystal X-ray diffraction and refined to an R-value of 0.039. The crystal structure is monoclinic with a = 1926(1), b = 801.4(3), c = 924(1) pm, β = 98.9(1)°, and is isomorphous with that of the analogous sulphur compound. The space group is P21/n with 4 molecules per cell, D(meas) = 1.733 g cm−3, D(calcd) = 1.726 g cm−3. The molecule has the syn-conformation with the largest possible Se—Se distance of 721.8 pm. The benzenoid rings form a dihedral angle of 19.1°. The distance between the internal aryl hydrogen atoms on rings 1 and 2 is 285.1 pm. The internal aryl C atoms are 314.6 pm apart. The 1Hmr solution spectra of 1a are consistent with the solid state structure, and can be explained without involving equilibration with an anti-conformer.

The Crystal and Molecular Structure of (PPh3)2PtO2•2CHCl3

1971 ◽  
Vol 49 (23) ◽  
pp. 3772-3777 ◽  
Author(s):  
P. T. Cheng ◽  
C. D. Cook ◽  
S. C. Nyburg ◽  
K. Y. Wan
Keyword(s):  
Crystal And Molecular Structure ◽  
Crystal Structure Analysis ◽  
Fold Axis ◽  
Transition Elements ◽  
Monoclinic System ◽  
X Ray ◽  
System A ◽  
Oxygen Complex ◽  
Axis Of Symmetry ◽  
Oxygen Complexes

The X-ray crystal structure analysis of the chloroform adduct of the bis(triphenylphosphine) platinum di-oxygen complex (PPh3)2PtO2•2CHCl3 is reported. The crystals belong to the monoclinic System a = 15.492(7), b = 13.520(5), c = 19.187(6) Å; β = 98.97(6)°. Space group C2/c. Z = 4 molecules per cell.A total of 2740 independent X-ray reflections were measured and refinement gave a final conventional R of 6.6%.The molecule has a two-fold axis of symmetry through the Pt atom with O—O normal to the axis. The O—O distance of 1.505(16) Å is in accord with that found with other transition elements when oxygen is taken up irreversibly to form di-oxygen complexes.

Observation of pseudo 10-fold symmetry in the ordered iron-zinc delta phase

1992 ◽  
Vol 50 (1) ◽  
pp. 36-37
Author(s):  
L. A. Giannuzzi ◽  
A. S. Ramani ◽  
P. R. Howell ◽  
H. W. Pickering ◽  
W. R. Bitler
Keyword(s):  
Single Phase ◽  
X Ray Diffraction ◽  
Rich Region ◽  
Average Cell ◽  
X Ray ◽  
Delta Phase ◽  
Cell Dimensions ◽  
Δ Phase ◽  
Morphological Differences ◽  
Concentration Discontinuity

The δ phase is a Zn-rich intermetallic, having a composition range of ∼ 86.5 - 92.0 atomic percent Zn, and is stable up to 665°C. The stoichiometry of the δ phase has been reported as FeZn7 and FeZn10 The deviation in stoichiometry can be attributed to variations in alloy composition used by each investigator. The structure of the δ phase, as determined by powder x-ray diffraction, is hexagonal (P63mc or P63/mmc) with cell dimensions a = 1.28 nm, c = 5.76 nm, and 555±8 atoms per unit cell. Later work suggested that the layer produced by hot-dip galvanizing should be considered as two distinct phases which are characterized by their morphological differences, namely: the iron-rich region with a compact appearance (δk) and the zinc-rich region with a columnar or palisade microstructure (δp). The sub-division of the δ phase was also based on differences in diffusion behavior, and a concentration discontinuity across the δp/δk boundary. However, work utilizing Weisenberg photographs on δ single crystals reported that the variation in lattice parameters with composition was small and hence, structurally, the δk phase and the δp phase were the same and should be thought of as a single phase, δ. Bastin et al. determined the average cell dimensions to be a = 1.28 nm and c = 5.71 nm, and suggested that perhaps some kind of ordering process, which would not be observed by x-ray diffraction, may be responsible for the morphological differences within the δ phase.

Low Molecular Weight Microfibers with Light Sensing Properties

2017 ◽  
Vol 54 (4) ◽  
pp. 655-658
Author(s):  
Andrei Bejan ◽  
Dragos Peptanariu ◽  
Bogdan Chiricuta ◽  
Elena Bicu ◽  
Dalila Belei
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight ◽  
X Ray Diffraction ◽  
Aromatic Rings ◽  
X Ray ◽  
Force Microscopy ◽  
Light Sensing ◽  
Sensing Applications ◽  
Atomic Force ◽  
Low Molecular Weight Compounds

Microfibers were obtained from organic low molecular weight compounds based on heteroaromatic and aromatic rings connected by aliphatic spacers. The obtaining of microfibers was proved by scanning electron microscopy. The deciphering of the mechanism of microfiber formation has been elucidated by X-ray diffraction, infrared spectroscopy, and atomic force microscopy measurements. By exciting with light of different wavelength, florescence microscopy revealed a specific optical response, recommending these materials for light sensing applications.

The crystal and molecular structure of tris(pentamethylenedithiocarbamate) chromium(III)-chloroform (1 : 2)

1981 ◽  
Vol 46 (1) ◽  
pp. 6-19 ◽  
Author(s):  
Viktor Kettman ◽  
Ján Garaj ◽  
Jaroslav Majer
Keyword(s):  
Molecular Structure ◽  
Structural Analysis ◽  
Crystal And Molecular Structure ◽  
Analysis Method ◽  
Complex Molecules ◽  
Coordination Polyhedra ◽  
X Ray ◽  
Cell Dimensions ◽  
Crustal Density ◽  
Unit Cell Dimensions

The crystal and molecular structure of [Cr(S2CN(CH2)5)3].2 CHCl3 was found by the X-ray structural analysis method. The value R 0.090 was found for 1 131 observed independent reflections. The substance crystallizes in a space group of symmetry P212121 with the following unit cell dimensions: a = 0.8675 (6), b = 1.815(2), c = 2.155(3) nm. The experimentally observed crustal density was 1.48 Mgm-3 and the value calculated for Z = 4 was 1.51 Mgm-3. The CrS6 coordination polyhedron has the shape of a trigonally distorted octahedron, where the D3 symmetry is a approximately retained. The degree of trigonal distortion expressed as the projection of the chelate S-Cr-S angle onto the plane perpendicular to the C3 pseudo axis is Φ = 41.7° (Φ = 60° for an octahedron). The skeleton of the structure formed by the complex molecules contains channels filled with chloroform molecules. The specific type of complex-chloroform interaction consists of the formation of hydrogen bonds of the chloroform protons with the fully occupied pπ-orbitals of the sulphur atoms in the coordination polyhedra. The low stability and crystal decomposition can be explained by loss of chloroform from the channels.

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