Acetic anhydride at 100 K: the first crystal structure determination

2016 ◽  
Vol 72 (10) ◽  
pp. 753-757 ◽  
Author(s):  
Rüdiger W. Seidel ◽  
Richard Goddard ◽  
Nils Nöthling ◽  
Christian W. Lehmann

Acetic anhydride (ethanoic anhydride), (CH3CO)2O, is a widely used acetylation reagent in organic synthesis. The crystal and molecular structure, as determined by single-crystal X-ray analysis at 100 K, is reported for the first time. A crystal of the title compound (m.p. 200 K) suitable for X-ray diffraction was grown from the melt at low temperature. The title compound crystallizes in the orthorhombic space groupPbcn, withZ= 4. In the crystal, the molecule adopts an exactC2-symmetric conformation about a crystallographic twofold axis. The molecules are densely packed. Two of the methyl H atoms form short intermolecular contacts to a neighbouring carbonyl O atom, which can be viewed as weak hydrogen bonds.

1980 ◽  
Vol 58 (8) ◽  
pp. 777-779 ◽  
Author(s):  
T. Stanley Cameron ◽  
Christine Chan ◽  
David G. Morris ◽  
Alistair G. Shepherd

The crystals belong to the orthorhombic space group C222, with a = 9.226, b = 12.092, c = 16.513 Å, Z = 4. A single crystal X-ray diffraction analysis has shown that the title compound, in which all carbon atoms are sp2 hybridized, exists with the ten membered ring in a slightly twisted tub conformation. The 13C nmr spectrum is also reported.


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°).


1983 ◽  
Vol 61 (7) ◽  
pp. 1603-1607 ◽  
Author(s):  
Kathy A. Beveridge ◽  
Gordon W. Bushnell ◽  
Reginald H. Mitchell

Conformations in a variety of cyclophane structures are discussed, as determined by X-ray diffraction in crystals and by 1Hmr in solution. Established nomenclature is brought forward (syn/anti and synclinal/anticlinal) and used to deal with an intermediate case which has been examined by both techniques. The crystal and molecular structure of the title compound, C16H16S4, is determined and refined to R = 0.0497. The crystal is orthorhombic, space group Pbca, a = 16.593(2), b = 10.018(2), c = 19.407(3) Å at 25(2) °C, Z = 8, Dcalc = 1.386 g cm−3. The molecular conformation in the crystal is anticlinal with a dihedral angle between the benzene rings of 101°. The benzene rings are displaced laterally by 0.727 Å and the sequence of torsion angles is similar in the two bridging chains.


2018 ◽  
Vol 6 (2) ◽  
pp. 132-136
Author(s):  
Pramod Kumar Yadav

The title compound azobenzene-4, 4′-dicarbonyl chloride has been synthesized in distilled dichlomethane and characterized by elemental analysis (C, H, N), IR and NMR (1H & 13C) studies. The crystal and molecular structure was further confirmed using single crystal X-ray diffraction analysis. It was crystallized in triclinic crystal system with space group P-1. The centrosymmetrically related molecules held together via C–H---O secondary interaction result in molecular aggregation of the compound.  Int. J. Appl. Sci. Biotechnol. Vol 6(2): 132-136


2019 ◽  
Vol 234 (9) ◽  
pp. 613-621
Author(s):  
Marc André Althoff ◽  
Jörn Frederik Martens ◽  
Marco Reichel ◽  
Manfred Metzulat ◽  
Thomas Matthias Klapötke ◽  
...  

Abstract The molecular and single crystal structure of O,O-diethyl O-[2-(dimethylamino)ethyl] phosphorothioate oxalate, as determined by single crystal X-ray diffraction studies, is described for the first time; although this compound is well-known by industry and research from the mid-20th century. The known decomposition product of pure O,O-diethyl O-[2-(dimethylamino)ethyl] phosphorothioate could also be structurally characterized. Additionally, the compounds are characterized by recent analytical methods e.g. NMR. The findings of our study support the thesis that the isolated decomposition product must be a by-product of the thiono-thiolo rearrangement process of the title compound.


1977 ◽  
Vol 55 (2) ◽  
pp. 333-339 ◽  
Author(s):  
Colin James Lyne Lock ◽  
Graham Turner

The crystal and molecular structure of the title compound has been examined by single crystal X-ray diffraction. The crystals are monoclinic with a = 28.045(10), b = 8.766(3), c = 12.376(5) Å, β = 91.14(3)°. The space group is C2/c and there are eight molecules per unit cell. A total of 5053 independent reflections, of which 2860 were observed, were examined on a Syntex [Formula: see text] diffractometer. The structure was refined by full matrix least squares to an R2 value of 0.0449. The ligands form a very rough octahedron around the rhenium atom with Re—Cl(1), 2.441(3); Re—Cl(2), 2.366(3), Re—O(1), 1.684(7); Re—O(2), 1.896(6); Re—N(1), 2.144(7); Re—N(2), 2.132(7) Å. The pyridine rings are a dominant factor in determining the details of the molecular structure.


1990 ◽  
Vol 43 (12) ◽  
pp. 2083 ◽  
Author(s):  
DC Craig ◽  
VJ James ◽  
JD Stevens

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.


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.


2006 ◽  
Vol 62 (3) ◽  
pp. 440-446 ◽  
Author(s):  
Hannes Krüger ◽  
Volker Kahlenberg ◽  
Karen Friese

The structure of metastable, incommensurately modulated Na2Si3O7 has been determined from single-crystal X-ray diffraction data. In contrast to previous investigations which stated that the compound crystallizes in an orthorhombic space group, this study shows that the compound is monoclinic with a pseudo-orthorhombic cell and is affected by twinning. The structure is described in the (3 + 1)-dimensional superspace. Crenel-type modulation functions are used to account for an aperiodic sequence of right- and left-handed zweier single chains of silicate tetrahedra. The modulation mainly affects one of the two symmetrically independent tetrahedral chains, which are connected to build up [Si3O7]2− layers. Sodium cations are coordinated by five oxygen ligands and provide linkage between adjacent tetrahedral sheets. Distortions of the silicate tetrahedra and crystal chemical relationships of the title compound to sodium and lithium di- and metasilicates are discussed in detail.


1981 ◽  
Vol 36 (2) ◽  
pp. 161-171 ◽  
Author(s):  
Joachim Fuchs ◽  
Axel Thiele ◽  
Rosemarie Palm

Abstract Dodecatungstosilicates free of crystal water were prepared for the first time by using tetraalkylammonium as cation. The crystal structure of the tetramethylammonium a-dodeeatungstosilicate [N(CH3)4]4SiW12O40 (1) and tetrabutylammonium) β-dodecatungstosilicate, [N(C4H9)4]4SiWi2040 (2) were solved by X-ray diffraction. (1) crystallizes tetragonal in the space group 14̅ with lattice parameters a = 14.642 Å; c= 12.706 Å; (2) orthorhombic, space group P212121 with a = 29.277 Å, b = 22.181 Å and c = 15.381 Å. The differences between the two isomeric heteropolyanions are discussed, especially the distances and angles between the tungsten atoms. Comparison of characteristic differences in the vibrational spectra permits the identification of the isomeric anions.


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