Synthesis, Crystal Structure and Intramolecular Interactions of 2-Methyl-3-(2-Methylphenyl)but-1-ene-1,1-dicarbonitrile (MMBD)

1996 ◽  
Vol 49 (9) ◽  
pp. 951 ◽  
Author(s):  
SJ Grabowski ◽  
SJ Grabowski ◽  
J Wilamowski ◽  
J Wilamowski ◽  
D Osman ◽  
...  

2-Methyl-3-(2-methylphenyl)but-1-ene-1,1-dicarbonitrile (MMBD) has been synthesized from 3-(o-tolyl)butan-2-one. The crystal and molecular structure of this compound was solved by X-ray diffraction, with estimated standard deviations ≤ � 0.005 Ǻ for bond lengths, and ≤ 0.3° for bond angles. Intramolecular interactions of the C≡N group, i.e. of the C-H...N, C-H...π (electrons) and C-H...C type, were observed, and the possibility of weak intramolecular hydrogen bridges in the molecule of MMBD was considered. The geometry of the MMBD molecule from AM1 calculations was compared with the X-ray structure.

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°).


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.


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.


1984 ◽  
Vol 39 (2) ◽  
pp. 145-148 ◽  
Author(s):  
Ulf Thewalt ◽  
Konrad Holl

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


1979 ◽  
Vol 57 (2) ◽  
pp. 174-179 ◽  
Author(s):  
A. Wallace Cordes ◽  
Paul F. Schubert ◽  
Richard T. Oakley

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.


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.


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.


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.


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.


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