Interaction of diiodine with some tetra-substituted dithiooxamides. Crystal and molecular structure of bis(morpholinothiocarbonyl)bis(diiodine)

1988 ◽  
Vol 66 (6) ◽  
pp. 1483-1489 ◽  
Author(s):  
Davide Atzei ◽  
Paola Deplano ◽  
Emanuele F. Trogu ◽  
Francesco Bigoli ◽  
Maria Angela Pellinghelli ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Charge Transfer ◽  
Solid State ◽  
Torsion Angle ◽  
Crystal And Molecular Structure ◽  
Formation Constants ◽  
Dalton Trans ◽  
X Ray ◽  
Space Groups ◽  
Spectrophotometric Methods

The reaction of some tetra-substituted dithiooxamides R2NC(S)C(S)NR2 (R = CH3:Me4dto; R = C2H5:Et4dto; R2N = OC4H8N:Mo2dto) with diiodine has been investigated by spectrophotometric methods in CHCl3. The formation in solution of 1:1 and 1:2 charge-transfer (c.t.) complexes between the reagents has been observed. A new computer program, derived from "SUPERQUAD" (P. Gans, A. Sabatini, and A. Vacca. J. Chem. Soc. Dalton Trans. 1195 (1985)), has been applied to evaluate the formation constants. The 1:2 c.t. complexes have been isolated in the solid state, and an X-ray structure analysis of the [OC4H8NC(S)C(S)NC4H8O]•2I2 compound indicated that the crystals are triclinic, space groups [Formula: see text], with a = 14.659(6), b = 15.111(6), c = 9.317(5) Å, α = 92.29(2), β = 99.71(2), γ = 99.48(2)° and Z = 4. In particular the torsion angle S—C—C—S (≈90°) shows that the conformation of the dithiooxamide is not trans.

Crystal and Molecular Structure of 3-(N-Methoxy-N-methylcarbamoyl)- 2,2,5,5-tetramethyl-1-oxy-pyrroline

2010 ◽  
Vol 65 (4) ◽  
pp. 475-478
Author(s):  
Guido D. Frey ◽  
Eberhardt Herdtweck
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Crystal And Molecular Structure ◽  
Layer Structure ◽  
Nitroxide Radical ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Stable Nitroxide

The crystal structure of the stable nitroxide radical 3-(N-methoxy-N-methylcarbamoyl)-2,2,5,5- tetramethyl-1-oxy-pyrroline was determined from single-crystal X-ray data: orthorhombic, space group Pbca (no. 61), a = 9.0213(1), b = 12.8625(1), c = 21.2406(2) Å, V = 2464.68(4) Å3 and Z = 8. The adjacent molecules assemble to a supramolecular layer structure in the solid state, linked by two intermolecular C-H...O hydrogen bonds.

Gehinderte Ligandbewegungen in Übergangsmetallkomplexen, XXXVII [1]: Photoreaktion von Dekacarbonyldirhenium mit Phenylallen / Hindered Ligand Motions in Transition Metal Complexes, XXXVII [1]: Photoreaction of Decacarbonyldirhenium with Phenylallene

1990 ◽  
Vol 45 (6) ◽  
pp. 793-802 ◽  
Author(s):  
Cornelius G. Kreiter ◽  
Wolfgang Michels ◽  
Reiner Exner
Keyword(s):  
Molecular Structure ◽  
Solid State ◽  
Transition Metal ◽  
Transition Metal Complexes ◽  
Crystal And Molecular Structure ◽  
Dinuclear Complexes ◽  
Rotation Barrier ◽  
Single Bond ◽  
Hindered Rotation ◽  
X Ray

Decacarbonyldirhenium (1) and phenylallene (2) form upon UV irradiation four dinuclear complexes: Decacarbonyl-μ-η1:1-(3,4-diphenyl-1,5-hexadien-2,5-diyl)-dirhenium (3), enneacarbonyl-μ-ηl:3-(3-phenyl-2-propen-1,2-diyl)-dirhenium (4), octacarbonyl-μ-hydrido-μ-η1:2-(3-phenyl-1,2-propadien-l-yl)-dirhenium (5) and octacarbonyl-μ-η2:2-(phenyl-1,2-propadiene)-dirhenium (6). The thermolabile complex 4 looses CO and forms the phenylallene bridged compound 6. Similarly 5 is rearranged to 6 by transfer of the hydrido ligand to the 3-phenyl-1,2-propadien-1-yl bridge. The formation of 3 and 4 can be rationalized via pentacarbonyl-phenylpropenediyl-rhenium radicals which dimerize to give 3 or add pentacarbonylrhenium radicals, loose CO and form 4. The crystal and molecular structure of 3 was determined by X-ray structure analysis. In the solid state the molecule is present in the ± ap conformation. In solution at 233 K the ±ap, +sc, and –sc conformations are equally populated. By a hindered rotation around a CC single bond, the three conformers are interconverted with a rotation barrier of ΔG*258 = 52.3 ± 1 kJ · mol-1.

Interaction of diiodine with Et4todit = 4,5,6,7-tetrathiocino [1,2-b:3,4-b′]diimidazolyl-1,3,8,10-tetraethyl-2,9-dithione. Crystal and molecular structure of Et4todit•2I2

1989 ◽  
Vol 67 (9) ◽  
pp. 1416-1420 ◽  
Author(s):  
Davide Atzei ◽  
Paola Deplano ◽  
Emanuele F. Trogu ◽  
Francesco Bigoli ◽  
Maria Angela Pellinghelli ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Charge Transfer ◽  
Charge Transfer Complex ◽  
Crystal And Molecular Structure ◽  
Equilibrium Constants ◽  
Structural Data ◽  
Monoclinic Space Group ◽  
X Ray ◽  
Transfer Structure ◽  
General Computer Program

Spectrophotometric studies on the reaction between diiodine and the title ligand in ratios ranging from 1:1 to 1:20 in CHCl3 have shown the formation of a 1:1 charge-transfer complex. A general computer program has been used to refine the equilibrium constant and the extinction coefficients simultaneously. In the solid state a 1:2 (donor to acceptor) complex has been isolated and an X-ray structure analysis of the compound indicated that the crystals are monoclinic, space group C2/c with a = 16.317(4), b = 13.912(3), c = 12.879(3) Å, β = 111.24(2)°, Z = 4.The molecular structure shows that two sulphur-thioamide atoms of the ligand act as donor with respect to two diiodine molecules. The structural data of the organic molecule of the complex and those of the free molecule are very similar. Keywords: diiodine, thioamides, charge-transfer, structure, equilibrium-constants.

Crystal structure – reactivity correlations in the solid state photochemistry of N-(tert-butyl)succinimide

1994 ◽  
Vol 72 (9) ◽  
pp. 1952-1960 ◽  
Author(s):  
Tai Y. Fu ◽  
John R. Scheffer ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Solid State ◽  
Crystalline State ◽  
Crystal And Molecular Structure ◽  
Carbonyl Oxygen ◽  
Hydrogen Atoms ◽  
X Ray ◽  
Tert Butyl ◽  
Close Contacts

In order to provide experimental evidence on the stereoelectronic requirements for intramolecular hydrogen atom abstraction by carbonyl oxygen, N-(tert-butyl)succinimide, 1, was investigated by the crystal structure – reactivity correlation method. In this method, the success or failure of a given reaction in the crystalline state is correlated with the geometric parameters associated with the process as determined by X-ray crystallography. In the case of N-(tert-butyl)succinimide, the crystal and molecular structure shows that the molecule adopts a conformation in which there are very close contacts (d = 2.17–2.24 Å) between the carbonyl oxygen atoms and certain γ-hydrogen atoms on the tert-butyl group. In accord with these close contacts, ultraviolet irradiation of N-(tert-butyl)succinimide in the crystalline state leads to transfer of one of the γ-hydrogen atoms from carbon to oxygen. This produces a 1,4-biradical which closes to form a cyclobutanol, and the cyclobutanol undergoes ring opening to afford the final stable product, tetrahydro-1H-azepine-2,5-dione, 2. The crystal and molecular structure of photoproduct 2 is also reported. In contrast to many solid state transformations, there was no discernable melting of the crystals during reaction, and complete conversions of 1 into 2 could be achieved. The isolated chemical yield of photoproduct 2 from the solid state reaction (79%) is in fact considerably higher than that reported by Kanaoka and Hatanaka for the corresponding solution phase process (49%). This permitted the solid state reaction to be followed to 100% conversion by X-ray powder diffractometry, which showed that the process is a single crystal-to-polycrystalline transformation involving a regular and progressive conversion of 1 into 2 with no obvious diffraction peaks that might be attributable to the intermediate cyclobutanol.

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.

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