The crystal structure of the trimethylsilyl derivative of the seven-membered ring silicate anion – [(CH3)3Si]14[Si7O21]

Abinitio molecular orbital calculations are reported for several cyclic and acyclic sulfones. The geometries of XSO2Y, where X, Y = H, F, or CH3 are optimized at the STO-3G* level. Similar calculations are reported for the smallest cyclic sulfone, thiirane-1,1 -dioxide, as well as the corresponding sulfoxide, thiirane-1-oxide, and the parent sulfide, thiirane. Where comparison with experiment is possible, the agreement is satisfactory. In order to consider the possibility of substantial differences between axial and equatorial S—O bonds in the gas phase, as observed in the crystal structure of 5H,8H-dibenzo[d,f][1,2]-dithiocin-1,1-dioxide, STO-3G* calculations are reported for a six-membered ring, thiane-1,1-dioxide, and a model eight-membered ring. Limited geometry optimization of the axial and equatorial S—O bonds in the chair conformations of the six- and eight-membered rings leads to bond lengths of 1.46 Å with the difference being less than 0.01 Å.

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Crystal structure of creatininium 5-(2,4-dinitrophenyl)-1,3-dimethylbarbiturate monohydrate: a potential anticonvulsant agent

Acta Crystallographica Section E Crystallographic Communications ◽

10.1107/s2056989016005247 ◽

2016 ◽

Vol 72 (5) ◽

pp. 620-623

Author(s):

Ponnusamy Poornima Devi ◽

Doraisamyraja Kalaivani

Keyword(s):

Crystal Structure ◽

Hydrogen Bonds ◽

Water Molecule ◽

Three Dimensional ◽

Pyrimidine Ring ◽

Membered Ring ◽

Anticonvulsant Agent ◽

The Mean ◽

Anions And Cations ◽

Molecular Salt

In the anion of the title hydrated molecular salt, C4H8N3O+·C12H9N4O7−·H2O [systematic name: 2-amino-1-methyl-4-oxo-4,5-dihydro-1H-imidazol-3-ium 5-(2,4-dinitrophenyl)-1,3-dimethyl-2,6-dioxo-1,2,3,6-tetrahydropyrimidin-4-olate monohydrate], the 2,4-dinitrophenyl ring is inclined to the mean plane of the pyrimidine ring [r.m.s. deviation = 0.37 Å] by 43.24 (8)°. The five-membered ring of the creatininium cation (2-amino-1-methyl-4-oxo-4,5-dihydro-1H-imidazol-3-ium) is essentially planar with an r.m.s. deviation of 0.015 Å. In the crystal, the anions and cations are linkedviaN—H...O hydrogen bonds, forming sheets parallel to theabplane. The sheets are linkedviaO—H...O hydrogen bonds involving the water molecule, forming a three-dimensional framework. Within the framework, there are C—H...O hydrogen bonds present. The title molecular salt displays anticonvulsant and hypnotic activities.

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Synthesis, crystal structure and molecular conformation of (±)-1-oxoferruginol and (±)-shonanol

Zeitschrift für Kristallographie - Crystalline Materials ◽

10.1524/zkri.219.10.659.50814 ◽

2004 ◽

Vol 219 (10) ◽

Author(s):

Swastik Mondal ◽

Monika Mukherjee ◽

Arnab Roy ◽

Debabrata Mukherjee

Keyword(s):

Crystal Structure ◽

Hydrogen Bonds ◽

Diffraction Data ◽

Molecular Conformation ◽

Membered Ring ◽

Methyl Groups ◽

Single Bond ◽

X Ray Diffraction ◽

X Ray ◽

Chemical Structures

Abstract(±)-1-oxoferruginol and (±)-shonanol, two potential intermediates in the synthesis of tricyclic diterpenoid ferruginol, have been prepared and crystal structures of the compounds have been investigated using single-crystal X-ray diffraction data. The methyl groups of the isopropyl moiety in (±)-shonanol are disordered over two positions with occupation factors 0.65(1) and 0.35(1), respectively. Although the chemical structures of two compounds are very similar, a C—C single bond in the terminal six-membered ring of (±)-1-oxoferruginol is replaced by a C=C bond in (±)-shonanol, the quantitative isostructurality index calculations indicate that the structures are not isostructural. Intermolecular O—H…O hydrogen bonds between pairs of molecules in the compounds related by center of inversion lead to characteristic dimers forming R

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ChemInform Abstract: The First Organo-Gallium Four-Membered Ring Compound with Arsenic, Halogen Mixed Bridging: Synthesis and Crystal Structure of Cyclic Ph2GaAs(SiMe3)2Ga(Ph)2Cl.

ChemInform ◽

10.1002/chin.198942263 ◽

1989 ◽

Vol 20 (42) ◽

Author(s):

R. L. WELLS ◽

W. K. HOLLEY ◽

S. SHAFIEEZAD ◽

A. T. MCPHAIL ◽

C. G. PITT

Keyword(s):

Crystal Structure ◽

Membered Ring ◽

Synthesis And Crystal Structure

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Additionen an die Si=N-Doppelbindung – Kristallstruktur eines (SiNCO)-Vierringes / Additions to the Si=N-Double Bond - Crystal Structure of a (SiNCO)-Four Membered Ring

Zeitschrift für Naturforschung B ◽

10.1515/znb-1991-0603 ◽

1991 ◽

Vol 46 (6) ◽

pp. 709-713 ◽

Cited By ~ 14

Author(s):

Susanne Vollbrecht ◽

Uwe Klingebiel ◽

Dieter Schmidt-Bäse

Keyword(s):

Crystal Structure ◽

Double Bond ◽

Single Crystals ◽

Membered Ring ◽

Thermal Cleavage

In the reaction with benzophenone and phenylaldehyde lithiated aminofluorosilanes behave like iminosilanes. Four membered rings are formed in (2+2) cycloadditions. The oxaazasilacyclobutane ((CMe3)2Si—NCMe3—C6H5CH—O—) was purified by destillation. Single crystals were obtained by recrystallization from hexane. The thermal cleavage of the (SiNCO)-rings leads to carboimines and cyclosiloxanes. The lithium derivate of di-tert-butylfluorosilyl-2.6-diisopropylphenylamine reacts with 2-methyl-propenal-2 in two competing ways. In a (2+4) cycloaddition an 1-oxa-3-aza-2-sila-5-cyclohexene is formed, and in a (2+2) cycloaddition 2-methyl-2-propenyl-N-(2.6-diisopropylphenyl)imine is generated via an (SiNCO)-ring intermediate.

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Crystal structure of tetraethyl 27,30-dioxo-7,12,20,25-tetra-tert-butyl-3,16-dioxa-9,22,28,31-tetrathiaheptacyclo[21.3.1.11,5.14,8.110,14.114,18.117,21]dotriaconta-4,6,8(29),10,12,17,19,21(32),23,25-decaene-2,2,15,15-tetracarboxylate

Acta Crystallographica Section E Crystallographic Communications ◽

10.1107/s205698901501748x ◽

2015 ◽

Vol 71 (10) ◽

pp. o778-o779

Author(s):

Mehmet Akkurt ◽

Jerry P. Jasinski ◽

Shaaban K. Mohamed ◽

Omran A. Omran ◽

Mustafa R. Albayati

Keyword(s):

Crystal Structure ◽

Hydrogen Bonds ◽

Title Compound ◽

Membered Ring ◽

Asymmetric Unit ◽

Axis Direction ◽

Tert Butyl ◽

Envelope Conformation ◽

Compound C ◽

A Chain

The asymmetric unit of the title compound, C54H64O12S4, consists of one half of the molecule, which is located on an inversion centre. The heterocyclic six-membered ring adopts a distorted envelope conformation with the spiro C atom as the flap. In the crystal, molecules are linked by weak C—H...O hydrogen bonds with anR22(14) motif, forming a chain along theb-axis direction.

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(Z)-3-Benzyl-1,5-benzothiazepin-4(5H)-one

Acta Crystallographica Section E Structure Reports Online ◽

10.1107/s1600536812029054 ◽

2012 ◽

Vol 68 (8) ◽

pp. o2329-o2329

Author(s):

V. Sabari ◽

R. Selvakumar ◽

M. Bakthadoss ◽

S. Aravindhan

Keyword(s):

Crystal Structure ◽

Hydrogen Bonds ◽

Title Compound ◽

Membered Ring ◽

Boat Conformation ◽

Compound C

In the crystal structure of the title compound, C16H13NOS, molecules are linked into cyclic centrosymmetricR22(8) dimersviapairs of N—H...O hydrogen bonds. The seven-membered ring adopts a boat conformation.

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The X-Ray Crystal Structure of 1,2-3,4-Di-O-isopropylidene-4-C-methylthiomethoxy-β-L-arabino-hexoseptanos-5-ulose

Australian Journal of Chemistry ◽

10.1071/ch9902083 ◽

1990 ◽

Vol 43 (12) ◽

pp. 2083 ◽

Cited By ~ 4

Author(s):

DC Craig ◽

VJ James ◽

JD Stevens

Keyword(s):

Crystal Structure ◽

Title Compound ◽

Membered Ring ◽

Boat Conformation ◽

X Ray Diffraction ◽

Orthorhombic Space Group ◽

Space Group ◽

X Ray

The crystal structure of the title compound (1) has been determined by X-ray diffraction. Crystals of (1) are orthorhombic, space group P21212 with a 11.425(1), b 24.916(1), c 5.8952(3)Ǻ, Z 4. Refinement on 1675 observed reflections measured with Cu Kα radiation converged at R 0.034. The seven- membered ring adopts a boat conformation in which the pseudo plane of symmetry passes through the ring oxygen.

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