The molecular structure of cyclopentadienyliron nitrosyl dimer; a novel compound containing an Fe_Fe double bond

1974 ◽  
Vol 63 (2) ◽  
pp. C16-C18
Author(s):  
J Calderón
Keyword(s):  
Molecular Structure ◽  
Double Bond

The Structure of Polyisoprenes. II. The Structure of β-Gutta-Percha

1945 ◽  
Vol 18 (2) ◽  
pp. 280-283
Author(s):  
G. A. Jeffrey
Keyword(s):  
Molecular Structure ◽  
Double Bond ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Interatomic Distances ◽  
Methyl Group ◽  
X Ray ◽  
Gutta Percha ◽  
Qualitative Estimate

Abstract The x-ray diffraction data at present available from β-gutta-percha are shown to be insufficient to distinguish fine details of molecular structure. Since a qualitative estimate of the intensities on the fibre diagram can be adequately satisfied by a model having normal interatomic distances and valency angles, no evidence exists for the improbable distortion of the methyl group out of the plane of the double bond previously ascribed to the molecule.

Group 6 metal carbonyl complexes of tridentate olefinic tertiary diphosphines. Crystal and molecular structure of {(E)-1,3-Bis[2-(diphenylphosphino)phenyl]-propene}tricarbonyltungsten(0),W(CO)3 {(E)-o-Ph2PC6H4CH=CHC6H4PPh2-o}

1980 ◽  
Vol 33 (6) ◽  
pp. 1261 ◽  
Author(s):  
MA Bennett ◽  
S Corlett ◽  
GB Robertson ◽  
WL Steffen
Keyword(s):  
Molecular Structure ◽  
Double Bond ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Metal Carbonyl ◽  
Free Ligand ◽  
Spectroscopic Studies ◽  
Carbonyl Complexes ◽  
X Ray Diffraction ◽  
Olefinic Double Bond

The ligands (L) (E)-2,2'-bis(diphenylphosphino)stilbene, (E)-o-Ph2PC6H4CH=CHC6H4PPh2-o (bdps), (E)-1,3-bis[2-(diphenylphosphino)phenyl]propene, (E)-o-Ph2PC6H4CH=CHCH2C6H4PPh2-o (bdpp), and (E)-1,3-bis[2-(diphenylphosphino)phenyl]but-1-ene,( E)-o-Ph2PC6H4CH=CHCHMeC6- H4PPh2-o (bdpb), form complexes of general formula M(CO)3L (M = Cr, Mo, W). N.m.r. (1H, 13C and 31P) and i.r. data indicate that the metal atoms are octahedrally coordinated by mutually trans phosphorus atoms and the double bond of the olefinic tertiary diphosphines and by meridionally disposed carbonyl groups. Conformational isomers of the complexes of bdpb can be detected by n.m.r, spectroscopy, but there is no evidence for similar conformers in the corresponding complexes of bdps and bdpp. The crystal and molecular structure of W(CO)3(bdpp),0.5CH2C12 has been determined by single-crystal X-ray diffraction analysis. The crystals are triclinic, space group PI, with a 10.1 13(Z), b 13.820(2), c 14.512(3) A, α 76.24(1), β 88.08(1), γ 76.31(1)°. The structure, solved by the heavy-atom method and refined to a conventional R of 0.049 for 8418 diffractometer data, confirms the conclusions drawn from spectroscopic studies. The olefinic double bond of bdpp is attached symmetrically to the metal atom [W-C(olefin) 2.403(8), 2.387(9) Ǻ] and is roughly parallel to the P-W-P axis. The C=C bond length of 1.359(11) Ǻ is only slightly longer than that expected for the free ligand and is indicative of relatively weak metal-olefin back-bonding. Other important bond lengths are: W-P 2.450(2), 2.462(2) Ǻ and W-C(C0) 2.020(7), 2.024(7) Ǻ (CO trans to CO) and 1.971(7) Ǻ (CO trans to olefin).

Structure cristalline et moléculaire d'un composé tricyclique contenant le cycle à dix chaînons dioxo diaza diphosphécine

1992 ◽  
Vol 70 (3) ◽  
pp. 809-816 ◽  
Author(s):  
Brigitte Duthu ◽  
Karim El Abed ◽  
Douraid Houalla ◽  
Robert Wolf ◽  
Joël Jaud
Keyword(s):  
Molecular Structure ◽  
Comparative Analysis ◽  
Double Bond ◽  
Mass Spectroscopy ◽  
Crystal And Molecular Structure ◽  
Accurate Information ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nmr Parameters ◽  
C Nmr

The sulfuration of the tricyclic organophosphorous dimer 2 leads easily to the dithiotricyclic derivative 3, which has been characterized by 31P, 1H, and 13C NMR, elemental analysis, and mass spectroscopy. Its crystal and molecular structure has been established by X-ray diffraction and compared to that of 2, which was previously determined. The comparative analysis of X-ray diffraction and NMR parameters gives accurate information about the molecular structure of both compounds. A numerical value of the anistropy cone of the P=S double bond is proposed. Keywords: phosphecine, NMR, X-ray, tricycle.

Chrom(0)-und Molybdän(0)-Komplexe von 11-Isopropyliden-bicyclo[4.4.1]undeca-2,4,8-trienen / Chromium(0) and Molybdenum(0) Complexes of 11-Isopropylidene-bicyclo[4.4. 1]undeca-2,4,8-trienes

1986 ◽  
Vol 41 (6) ◽  
pp. 722-730 ◽  
Author(s):  
Cornelius G. Kreiter ◽  
Eduard Michels ◽  
Jürgen Kaub
Keyword(s):  
Molecular Structure ◽  
Double Bond ◽  
Nmr Spectroscopy ◽  
Transition Metals ◽  
Crystal And Molecular Structure ◽  
Double Bonds ◽  
Conjugated Diene ◽  
X Ray ◽  
Ir And Nmr Spectroscopy ◽  
Elemental Analyses

11-Isopropylidene-bicyclo[4.4.1]undeca-2,4,8-triene (IBU, 1A) and five alkyl substituted de­rivatives (1B-1F) contain a conjugated diene unit and two isolated CC-double bonds, one exocyclic and one incorporated into the bicvclus, each suited for complexation to transition metals. With [Cr(CO)3(CH3CN)3] (2) 1A-1F form [Cr(CO)3(η6-IBU)] complexes (3A−3F). in which the IBU ligands are coordinated to the chromium via the diene unit and the exocyclic CC-double bond. The corresponding [Mo(CO)3(η6-IBU)] complexes (5A−5F) are obtained from the reactions of [Mo(CO)3(diglyme)] (4) with 1A−1F. In addition, the isomeric [Mo(CO)3(η6-IBU)] complexes (6A−6D) are formed, in which the IBU ligands are bound to molybdenum via the three cyclic CC-double bonds. The complexes 3A−3F, 5A−5F and 6A−6D were studied by IR and NMR spectroscopy (1H. 13C) and characterized by C, H elemental analyses. The crystal and molecular structure of 1A was determined by X-ray structure analysis.

Transmission of Molecular Structure on NMR Characteristics of Phosphorus-Nitrogen Double Bond Systems

1999 ◽  
Vol 147 (1) ◽  
pp. 103-103
Author(s):  
Dietrich Gudat ◽  
Edgar Niecke ◽  
Gisbert Grossmann ◽  
Kerstin Krüger
Keyword(s):  
Molecular Structure ◽  
Double Bond ◽  
Nitrogen Double Bond

Structure of [μ-S2{Ru(PCy3)('S4')}2] · 2.5 THF ·0.5 Et2O Containing Homochiral Metal Complex Fragments ['S4'2- = 1,2-Bis(mercaptophenylthio)-ethane (2-)]

1999 ◽  
Vol 54 (9) ◽  
pp. 1122-1124 ◽  
Author(s):  
Dieter Sellmann ◽  
Frank W. Heinemann ◽  
Torsten Gottschalk-Gaudig
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Double Bond ◽  
Metal Complex ◽  
Title Compound ◽  
Direct Methods ◽  
Uv Spectrum ◽  
Triclinic Space Group ◽  
X Ray ◽  
Bond Character

A crystal of the title compound [μ-S2{Ru(PCy3)(′S4′)}2] · 2.5 THF · 0.5 Et2O (1 · 2.5 THF · 0.5 Et2O), grown from a THF/Et2O solution, was investigated by single-crystal X-ray analysis. 1 · 2.5 THF · 0.5 Et2O crystallizes in the triclinic space group P1̄ with a = 14.209(4), b = 15.390(4), c = 19.526(6) Å, α = 111.29(2), ß = 100.43(2), γ = 95.65(2)°, and Z = 2. The crystal structure was solved by direct methods (wR2= 0.1520 for 12565 reflections; R1 = 0.0507 for 9205 observed reflections). The molecular structure of 1 · 2.5 THF · 0.5 Et2O is characterized by a trans η1 -η1-S2 bridge connecting two homochiral [Ru(PCy3)(′S4′)] fragments. The S-S bond length of 1.982(2) Å and a mean Ru-S(bridge) distance of 2.234(2) Å indicate partial double bond character of these bonds. The RuSSRu unit in 1 · 2.5 THF · 0.5 Et2O is a chromophore as indicated by its UV spectrum and can be described by a delocalized 4c-6e 7π system.

scholarly journals Crystal structure and Hirshfeld surface analysis of a chalcone derivative: (E)-3-(4-fluorophenyl)-1-(4-nitrophenyl)prop-2-en-1-one

2019 ◽  
Vol 75 (1) ◽  
pp. 53-57
Author(s):  
Qin Ai Wong ◽  
Tze Shyang Chia ◽  
Huey Chong Kwong ◽  
C. S. Chidan Kumar ◽  
Ching Kheng Quah ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bond ◽  
Double Bond ◽  
Benzene Ring ◽  
Surface Analysis ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
Chalcone Derivative ◽  
Centroid Distance

The molecular structure of the title chalcone derivative, C15H10FNO3, is nearly planar and the molecule adopts a trans configuration with respect to the C=C double bond. The nitro group is nearly coplanar with the attached benzene ring, which is nearly parallel to the second benzene ring. In the crystal, molecules are connected by pairs of weak intermolecular C—H...O hydrogen bonds into inversion dimers. The dimers are further linked by another C—H...O hydrogen bond and a C—H...F hydrogen bond into sheets parallel to (104). π–π interactions occur between the sheets, with a centroid–centroid distance of 3.8860 (11) Å. Hirshfeld surface analysis was used to investigate and quantify the intermolecular interactions.

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