Empirical relations between disulfide bond lengths, (nitrogen or carbon)-carbon-sulfur-sulfur torsion angles, and substituents in aromatic disulfides. Crystal and molecular structure of 3,3'-dihydroxydi-2-pyridyl disulfide

1978 ◽  
Vol 100 (26) ◽  
pp. 8101-8106 ◽  
Author(s):  
Lois S. Higashi ◽  
Munime Lundeen ◽  
Karl Seff
Keyword(s):  
Molecular Structure ◽  
Disulfide Bond ◽  
Crystal And Molecular Structure ◽  
Torsion Angles ◽  
Bond Lengths ◽  
Empirical Relations

Redetermination of the Crystal and Molecular Structure of Cyclohexasulfur, S6 [1]

1978 ◽  
Vol 33 (12) ◽  
pp. 1554-1555 ◽  
Author(s):  
Jürgen Steidel ◽  
Joachim Pickardt ◽  
Ralf Steudel
Keyword(s):  
Molecular Structure ◽  
Structural Analysis ◽  
Low Temperature ◽  
Single Crystals ◽  
Crystal And Molecular Structure ◽  
Torsion Angles ◽  
X Ray ◽  
Bond Angles

A low temperature (-90 °C) X-ray structural analysis of S6 single crystals yielded improved data for the bond distances (206.8 pm), bond angles (102.6°), and torsion angles (73.8°) of the D3d molecule which are in agreement with current theories of homonuclear sulfur bonds.

Spaltung von S4N4 zu S2N2 bei Raumtemperatur: Darstellung und Struktur von S2N2 • 2AlBr3 / Cleavage of S4N4 to S2N2 at Room Tem perature: Preparation and Structure of S2N2 • 2AlBr3

1984 ◽  
Vol 39 (2) ◽  
pp. 145-148 ◽  
Author(s):  
Ulf Thewalt ◽  
Konrad Holl
Keyword(s):  
Molecular Structure ◽  
Room Temperature ◽  
Crystal And Molecular Structure ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Lengths

The compound S2N2 • 2AlBr3 has been prepared by reaction of S4N4 with AlBr3 in 1,2-dibromoethane at room temperature. Its crystal and molecular structure have been determined by X-ray diffraction; R = 0.068. Crystal data: monoclinic, P 21/n, a = 9.594(5), b = 9.975(4), c = 7.528(4) Å , β = 111.36(5)°. The S2N2 ring of the centrosymmetrical complex is bonded via its nitrogen atoms to two AlBr3 units thus completing coordination tetrahedra around the Al atoms. Bond distances and angles within the S2N2 ring are d(S-N) = 1.629(13) and 1.651(13) Å, ∢ (S-N-S) = 95.8, and ∢ (N-S-N) - 84.2°. Whereas the S-N bond lengths agree closely with those of free S2N2, the angle at N is enlarged by ca. 5° and the angle at S is decreased by ca. 5°. The sulfur atoms form two close S···Br contacts of length 3.149 (intramolecular) and 3.193 (intermolecular) Å , respectively. The intermolecular attractive nonbonded S···Br interactions tie the complexes together in a way that leads to infinite chains which run parallel to the crystallographic z axis

The crystal and molecular structure of anti-1,2,4,5-tetraphenyl-3,6-dicarbomethoxytricyclo[3.1.0.02,4]hexane

1978 ◽  
Vol 56 (10) ◽  
pp. 1364-1367 ◽  
Author(s):  
M. J. Bennett ◽  
J. T. Purdham
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Experimental Error ◽  
Crystal And Molecular Structure ◽  
Structural Data ◽  
Monoclinic Space Group ◽  
Full Matrix ◽  
Bond Lengths ◽  
Highly Strained ◽  
Least Squares Techniques

1,2,4,5-Tetraphenyl-3,6-dicarbornethoxytricyclo[3.1.0.02,4]hexane crystallizes in the monoclinic space group P21/c with a = 10.044(4), b = 9.500(2), c = 14.172(4) Å, β = 104.38(2)°, and Z = 2. Using 1032 unique reflections with I > 3σ(I), the structural data were refined by full matrix least-squares techniques to R = 0.038. The molecule was found to be in the anti-configuration. All bond lengths within the highly strained central tricyclic framework were equal within experimental error and average 1.531 Å.

Kristall-und Molekülstruktur von N-(TricHorgermyl)-trimethylphosphinimin [Cl3Ge-N=PMe3]n, n = 1 und 2 / Crystal and Molecular Structure of N-(Trichlorogermyl)-trimethylphosphinimine [Cl3Ge-N=PMe3]n, n= 1 and 2

1978 ◽  
Vol 33 (5) ◽  
pp. 493-497 ◽  
Author(s):  
W. S. Sheldrick ◽  
D. Schomburg ◽  
W. Wolfsberger
Keyword(s):  
Molecular Structure ◽  
Bond Length ◽  
Crystal And Molecular Structure ◽  
Unit Cell ◽  
Centrosymmetric Dimer ◽  
Triclinic Space Group ◽  
Bond Lengths ◽  
Axial Ligands ◽  
Trigonal Bipyramidal ◽  
Coordinate Bond

Abstract N-(Trichlorogermyl)trimethylphosphinimine crystallizes in the triclinic space group P1̅ with a = 12.49(2), b = 12.54(3), c = 6.66(1) Å,a = 100.96(10),β = 91.45(14), γ = 102.77(15)°. The structure was solved by Patterson and difference syntheses and refined to R = 0.063 for 2867 independent reflections. In the unit cell there are two symmetry related monomers containing tetracoordinated Ge and one crystallographically centrosymmetric dimer with a planar four-membered [GeN]2 ring exhibiting trigonal-bipyramidal pentacoordinated Ge and trigonal N. Significant differences are observed in the bond lengths from pentacoordinated Ge to its equatorial and axial ligands: Ge-Neq 1.837(7), Ge-Nax 1.972(7), Ge-Cleq 2.176(2) and 2.170(2), Ge-Clax 2.345(3) Å. The Ge-Neq distance is similar to that observed in tetracoordinated derivatives [1.81-1.87 Å], whereas the Ge-Nax distance is 0.22 Å shorter than that observed for the axial N→Ge coordinate bond in hitherto known pentacoordinated derivatives [2.19-2.24 Å]. The very short Ge-N bond length of 1.737(8) Å in the monomer which is 0.07 Å shorter than in other tetracoordinated derivatives may be indicative of the involvement of a (p→d)π component.

Crystal and molecular structure of difluoroboron N-methylacethydroxamate (2,2-difluoro-4,5-dimethyl-1,3-dioxa-4-azonia-2-boranatacyclopent-4-ene)

1977 ◽  
Vol 55 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Steven J. Rettig ◽  
James Trotter ◽  
W. Kliegel ◽  
D. Nanninga
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths

Crystals of difluoroboron N-methylacethydroxamate are monoclinic, a = 5.097(1), b = 10.653(2), c = 11.520(2) Å, β = 103.57(2)°, Z = 4, space group P21/c. The structure was solved by direct methods and was refined by full-matrix least squares procedures to a final R of 0.056 and Rw of 0.077 for 988 reflections with I ≥ 3σ(I). The structure features a planar five-membered BO2CN ring. Bond lengths (corrected for libration) are: B—F, 1.374(3) and 1.381(3), O—B, 1.496(3) and 1.497(3), O—N, 1.349(2), O—C, 1.346(2), C—N, 1.298(3) and 1.458(3), and C—C, 1.468(3) Å.

The crystal and molecular structure of 1,4-diphenyl-2,2′,3,3′,5,5′,6,6′-octamethylcyclo-1,4-diphospha-2,3,5,6-tetrasilahexane, a phosphorus–silicon heterocycle

1979 ◽  
Vol 57 (2) ◽  
pp. 174-179 ◽  
Author(s):  
A. Wallace Cordes ◽  
Paul F. Schubert ◽  
Richard T. Oakley
Keyword(s):  
Molecular Structure ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Chair Conformation ◽  
Monoclinic Space Group ◽  
Single Bond ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Bond Lengths

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.

Synthesis and crystal and molecular structure of ethanolaminogallium dimethyl, H2NCH2CH2O•GaMe2

1979 ◽  
Vol 57 (5) ◽  
pp. 586-590 ◽  
Author(s):  
Kenneth S. Chong ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bonds ◽  
Physical Properties ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Space Group ◽  
Bond Lengths ◽  
R Value

Details of the synthesis and physical properties of H2NCH2CH2O•GaMe2 are given. The compound crystallizes in the tetragonal space group P43, a = 12.2771(2), c = 9.7345(4) Å, Z = 8. The structure was solved by Patterson and Fourier syntheses and was refined by fullmatrix least-squares procedures to a final R value of 0.028 and Rw of 0.036 for 1378 reflections with I ≥ 3σ(I). The structure consists of monomeric molecules containing tetrahedrallycoordinated gallium atoms. Molecules are linked by an extensive network of N—H … O hydrogen bonds. Bond lengths (corrected for libration) are: Ga—O, 1.916(5) and 1.917(4), Ga—N, 2.056(6) and 2.072(6), and Ga—C, 1.962–1.974(8–9) Å.

Crystal and molecular structure of [dimethyl(1-pyrazolyl)(2-pyridyl-methoxy)gallato-N2,O,N3](η3-allyl)dicarbonylinolybdenum(II)

1988 ◽  
Vol 66 (3) ◽  
pp. 355-358 ◽  
Author(s):  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Nitrogen Atom ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Coordination Geometry ◽  
Pyridyl Nitrogen ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths

Crystals of [dimethyl(1-pyrazolyl)(2-pyridylmethoxy)gallato-N2,O,N3](η3-allyl)dicarbonylmolybdenum(II) are triclinic, a = 9.632(2), b = 9.798(2), c = 10.255(2) Å, α = 80.16(1), β = 87.38(1), γ = 81.75(1)°, Z = 2, space group [Formula: see text]. The structure was solved by conventional heavy-atom methods and was refined by full-matrix least-squares procedures to R = 0.033 and Rw = 0.037 for 3000 reflections with I ≥ 3σ(I). The molecule has pseudo-octahedral coordination geometry with the tridentate [Me2Ga(N2C3H3)(OCH2(C5H4N))]− ligand facially coordinated and the η3-allyl ligand occupying one coordination site trans to the pyridyl nitrogen atom. Important bond lengths are Mo—O = 2.219(2), Mo—N(py) = 2.212(3), Mo—N(pz) = 2.232(2), Mo—C(allyl) = 2.290(4), 2.189(4), 2.341(4), Mo—CO (trans to O) = 1.928(4), and Mo—CO (trans to N) = 1.952(4) Å.

Crystal and molecular structure of L-prolinatodiphenylboron

1977 ◽  
Vol 55 (6) ◽  
pp. 958-965 ◽  
Author(s):  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Conformational Disorder ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths

Crystals of L-prolinatodiphenylboron are monoclinic, a = 5.9427(5), b = 14.4633(7), c = 8.9654(4) Å, β = 98.423(8)°, Z = 2, space group P21. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.037 and Rw of 0.053 for 1477 reflections with I ≥ 3σ(I). The proline ring exhibits conformational disorder. The crystal structure consists of discrete molecules linked by N—H … O hydrogen bonds (N … O = 2.893(3) Å) along the short a axis. Intramolecular N—B coordination occurs to form a system of two fused five-membered rings. Bond lengths (corrected for libration) are: N—B, 1.630(3), O—B, 1.529(3), O—C, 1.219(3) and 1.300(3), N—C, 1.506(3) and 1.507(3), C(sp3)–C(sp3), 1.525(4), C(sp2)—C(sp3), 1.517(3), and mean C—C(phenyl), 1.394 Å.

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