Molecular and Crystal Structure of Two Cyclobuten-3,4-dione Derivatives: The Dithallium Salt of 1,2-Dicyanimino-(TI2CMCB) and the 1,2-Diiodocyclobuten-3,4-dione (I2CB)

1989 ◽  
Vol 44 (2) ◽  
pp. 169-174 ◽  
Author(s):  
Bruno Lunelli ◽  
Magda Monari

Abstract The crystal and molecular structure of the dithallium salt of the 1,2-dicyanim inocyclobuten-3,4-dione dianion and of 1,2-diiodocyclobuten-3,4-dione, determined by X-ray diffraction, are reported and discussed. Results of FT-IR and calorimetric measurements are also presented.

1986 ◽  
Vol 51 (11) ◽  
pp. 2521-2527 ◽  
Author(s):  
Jan Lokaj ◽  
Eleonóra Kellö ◽  
Viktor Kettmann ◽  
Viktor Vrábel ◽  
Vladimír Rattay

The crystal and molecular structure of SnBu2(pmdtc)2 has been solved by X-ray diffraction methods and refined by a block-diagonal least-squares procedure to R = 0.083 for 895 observed reflections. Monoclinic, space group C2, a = 19.893(6), b = 7.773(8), c = 12.947(8) . 10-10 m, β = 129.07(5)°, Z = 2, C20H38N2S4Sn. Measured and calculated densities are Dm = 1.38(2), Dc = 1.36 Mg m-3. Sn atom, placed on the twofold axes, is coordinated with four S atoms in the distances Sn-S 2.966(6) and 2.476(3) . 10-10 m. Coordination polyhedron is a strongly distorted octahedron. Ligand S2CN is planar.


1997 ◽  
Vol 52 (2) ◽  
pp. 256-258 ◽  
Author(s):  
Evgeni V. Avtomonov ◽  
Rainer Grüning ◽  
Jörg Lorberth

Abstract The crystal structure of the title compound has been determined by X-ray diffraction methods. Due to the Lewis acidic character of the iodine substituent a “zig-zag” chain is formed via intermolecular interactions (2.933(4) A) between iodine and oxygen atoms of theocarbamate moiety. A three-dimensional network is formed through hydrogen-bridging (2.04 A) between NH-groups and the oxygen atoms of the neighbouring carbamate group of the next molecule.


1989 ◽  
Vol 44 (1) ◽  
pp. 5-8
Author(s):  
Michel Mégnamisi-Bélombé

Abstract trans-Dichloro(ethanedial-dioximato)(ethanediaI-dioxime)rhodium (III), RhCl2(GH)(GH2), has been synthesized and its structure determined by single crystal X-ray diffraction at room temperature. C4H7Cl2N4O4Rh, Mr = 348.94. monoclinic space group P21/ɑ; a = 10.543(3), b = 8.363(2), c = 11.512(3)Å ; β = 92.79(2)°; V = 1024Å3; Z = 4; Dc = 2.26 Mg m-3. Final Rw = 0.075 for 2035 reflections and 139 parameters. The coordination geometry around Rh is a dis­torted (4+2) octahedron, with four chelating N atoms lying in the equatorial plane and the two Cl atoms in the apical positions. The H atoms of the oxime groups are involved in relatively weak intramolecular O-H-O bridgings, as well as in very strong intermolecular bridgings which extend throughout the crystal structure and propagate nearly parallel to the [101] crystallographic direction.


1998 ◽  
Vol 53 (5-6) ◽  
pp. 634-636 ◽  
Author(s):  
Martina Näveke ◽  
Armand Blaschette ◽  
Peter G. Jones

Abstract The crystal structure of the known title compound was determined by low-temperature X-ray diffraction (orthorhombic, space group Pbcn, Z = 4). The molecule displays an unusually short O-N bond, a relatively long C-O bond and a moderately pyramidal O-NS2 skeleton (O-N 133.1, C-O 148.5 pm, sum of bond angles at N: 347.4°).


1987 ◽  
Vol 65 (6) ◽  
pp. 1322-1326 ◽  
Author(s):  
Hong Wang ◽  
Richard J. Barton ◽  
Beverly E. Robertson ◽  
John A. Weil ◽  
Keith C. Brown

The crystal structure of 9-(2,4,6-trinitroanilino)-carbazole, C18H11N5O6, has been determined by X-ray diffraction. Crystals are monoclinic, space group P21/c, a = 14.686(11), b = 24.601(12), c = 10.047(5) Å, β = 107.76(5)° at 292 K, with Z = 8. The two nitrogen atoms in the central fragment have a staggered conformation with an N—N distance of 1.381(4) Å, which is considerably shorter than N—N distances in related N-picrylhydrazine molecules. The picryl moiety has a geometry similar to that of related N-picrylhydrazine molecules. The title compound contains an [Formula: see text] intramolecular bond to one of the ortho nitro groups on the picryl ring. The carbazole plane of one molecule and the picryl plane of a neighboring molecule overlap to form an infinite linear chain of the form … DhA:DhA … where D represents the carbazole donor, h the linear chain linkage within the molecule, and A represents the picryl acceptor of one molecule. The two interplanar distances between D of one molecule and A of an adjacent molecule are 3.28(13) and 3.34(13) Å, indicating a strong π-molecular interaction.


Author(s):  
A. Whitaker

AbstractThe crystal and molecular structure of C.I. Pigment Red 2, l′-(2,5-dichlorophenyl)azo-2′-hydroxy-3′-phenylamidonaphthalene has been determined by x-ray diffraction techniques. It crystallizes in the monoclinic system with cell parametersThe hydrogen atoms have been found and included but not refined. The final residual is 15.3%. The molecule is probably in the form of the hydrazone tautomer. The intramolecular hydrogen bonds keep most of the molecule approximately planar while it appears that the remainder is held in the same plane due to steric hinderence between the molecules. The molecules are packed in columns with alternate molecules antiparallel and are linked by van der Waals forces.


1989 ◽  
Vol 67 (1) ◽  
pp. 48-53 ◽  
Author(s):  
David Eric Berry ◽  
Jane Browning ◽  
Gordon William Bushnell ◽  
Keith Roger Dixon ◽  
Alan Pidcock

Reaction of "cyclamphosphorane" (cyclamPH) with [Pt2Cl4(PEt3)2] yields [PtCl(PEt3)(cyclamPH)]Cl. The complex crystallizes as a dichloromethane solvate in the monoclinic space group P21/n, with a = 13.877(3), b = 23.231(7), c = 8.295(2)Å, β = 91.86(4)°, and an X-ray diffraction study shows square planar platinum coordination in which the labile proton of cyclamPH has transferred from phosphorus to nitrogen and the ligand is attached via simple [Formula: see text] chelation. The phosphorus is trans to chlorine in the platinum coordination plane.The corresponding product, trans-[PtCl2(PEt3)(cyclenPH2)]Cl, derived from reaction of "cyclenphosphorane" (cyclenPH) with [Pt2Cl4(PEt3)2], is shown by NMR studies to have a quite different structure in which the ligand is protonated at two nitrogen sites but not at phosphorus. The phosphorus is pentacoordinate with four attachments to nitrogen atoms and one to platinum. The two chlorine atoms are mutually trans in the platinum coordination plane. Keywords: crystal structure, cyclenphosphorane reaction, cyclamphosphorane reaction, X-ray diffraction.


1983 ◽  
Vol 36 (4) ◽  
pp. 683 ◽  
Author(s):  
BF Hoskins ◽  
RJ Steen

The crystal structure of the complex Mn2(CO)8(dam) (dam = Ph2AsCH2AsPh2) has been determined by three-dimensional X-ray diffraction methods. The crystals are triclinic, space group P1, with a 11.191(1), b 16.498(5), c 9.455(1) �, a 93.64(2), β 109.08(2), γ 89.36(2)� and contain two discrete, binuclear molecules of Mn2(CO)8(dam) per unit cell. The structure, solved by direct and Fourier methods, was refined by a least-squares procedure to R and Rw of 0.065 and 0.082 respectively for 1907 independent, statistically significant reflections collected by counter methods. The feature of particular interest in this compound is the accommodation of the bridging bidentate dam ligand [As.. .As separation 3.242(2) �] across a shorter Mn�-Mn� bond [2.962(3) �] which constrains the molecule so that a much less staggered configuration of the two manganese coordination octahedra is observed relative to the parent compound Mn2(CO)10, the rotation of the two equatorial planes in the former being 30�.


2011 ◽  
Vol 415-417 ◽  
pp. 1443-1446
Author(s):  
Ke Liang Zhang ◽  
Ning Sheng Zhang ◽  
Chen Tun Qu

The title compound has been prepared from the reaction of fluorescein and 1-bromobutane in the presence of potassium carbonate. Its crystal and molecular structure is determined by single crystal X-ray diffraction. Its crystal is monoclinic space group P2(1)/n with lattice parameters: a = 8.0460(19) Å, b = 13.198(3) Å, c = 22.208(5) Å, α = 90.00º, β = 94.140(3)º, γ = 90.00º, V= 2352.1(9)Å3, Density (calculated) 1.228 mg /m3, μ(mm-1) = 0.08, absorption coefficient = 0.082m−1, F(000) 1034, Z = 4. In the crystal structure, intermolecular O-H hydrogen bands are responsible for the formation of a 3-dimensional net-work. The UV-vis absorption and fluorescence spectra of both dibutyl ester-ether fluorescein was studied.


1984 ◽  
Vol 49 (10) ◽  
pp. 2363-2370
Author(s):  
Viktor Vrábel ◽  
Ernest Šturdík ◽  
Michal Dunaj-Jurčo ◽  
Jan Lokaj ◽  
Ján Garaj

The crystal structure of carbonylcyanide-4-chlorophenylhydrazone was solved by the single crystal X-ray diffraction method and interpreted by the heavy atom method. The compound crystallizes in the P21/c monoclinic group with 4 molecules per unit cell and with lattice parameters: a = 1.1843(3), b = 0.5944(1), c = 1.4922(3) nm and β = 117.92(2)°. The structure was refined by the least squares method for 1 078 observed reflections to a final value of R = 4.9%. The crystal structure consists of monomeric units, where hydrogen bonds were observed between atoms N3...H5 0.2193 nm and N3...H3 0.2404 nm between two molecules transformable through centre of symmetry -x, -y, -z. The name 4-chlorophenylhydrazonopropanedinitrile is recommended for the studied compound on the basis of this X-ray structural analysis.


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