Structural and computational analysis of published neutron diffraction data show that crystalline vitamin B12 coenzyme contains a strong intramolecular N-H...Ph hydrogen bond

1998 ◽  
Vol 54 (1) ◽  
pp. 94-96 ◽  
Author(s):  
E. B. Starikov ◽  
T. Steiner
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Neutron Diffraction ◽  
Computational Analysis ◽  
Side Chain ◽  
Vitamin B ◽  
Neutron Diffraction Data ◽  
Acta Cryst ◽  
Benzimidazole Group ◽  
Aromatic Hydrogen

The neutron diffraction crystal structure of vitamin B12 coenzyme [Bouquiere et al. (1993). Acta Cryst. B49, 79–89] contains a yet unnoticed intramolecular aromatic hydrogen bond donated by a propionamide side chain and accepted by the benzimidazole group. The distance from the H-atom to the aromatic midpoint is only 2.58 Å and the bond energy is calculated to be 16.7 kJ mol−1.

A structural study of (1RS,2SR,3RS,4SR,5RS)-2,4-dibenzoyl-1,3,5-triphenylcyclohexan-1-ol chloroform hemisolvate and (1RS,2SR,3RS,4SR,5RS)-2,4-dibenzoyl-1-phenyl-3,5-bis(2-methoxyphenyl)cyclohexan-1-ol

2015 ◽  
Vol 71 (6) ◽  
pp. 491-498 ◽  
Author(s):  
Mikhail E. Minyaev ◽  
Dmitrii M. Roitershtein ◽  
Ilya E. Nifant'ev ◽  
Ivan V. Ananyev ◽  
Tatyana V. Minyaeva ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Single Crystals ◽  
Structural Study ◽  
Chair Conformation ◽  
Cyclohexane Ring ◽  
Nmr Studies ◽  
Acta Cryst

(1RS,2SR,3RS,4SR,5RS)-2,4-Dibenzoyl-1,3,5-triphenylcyclohexan-1-ol or (4-hydroxy-2,4,6-triphenylcyclohexane-1,3-diyl)bis(phenylmethanone), C38H32O3, (1), is formed as a by-product in the NaOH-catalyzed synthesis of 1,3,5-triphenylpentane-1,5-dione from acetophenone and benzaldehyde. Single crystals of the chloroform hemisolvate, C38H32O3·0.5CHCl3, were grown from chloroform. The structure has triclinic (P-1) symmetry. One diastereomer [as a pair of (1RS,2SR,3RS,4SR,5RS)-enantiomers] of (1) has been found in the crystal structure and confirmed by NMR studies. The dichoromethane hemisolvate has been reported previously [Zhanget al.(2007).Acta Cryst.E63, o4652]. (1RS,2SR,3RS,4SR,5RS)-2,4-Dibenzoyl-3,5-bis(2-methoxyphenyl)-1-phenylcyclohexan-1-ol or [4-hydroxy-2,6-bis(2-methoxyphenyl)-4-phenylcyclohexane-1,3-diyl]bis(phenylmethanone), C40H36O5, (2), is also formed as a by-product, under the same conditions, from acetophenone and 2-methoxybenzaldehyde. Crystals of (2) have been grown from chloroform. The structure has orthorhombic (Pca21) symmetry. A diastereomer of (2) possesses the same configuration as (1). In both structures, the cyclohexane ring adopts a chair conformation with all bulky groups (benzoyl, phenyl and 2-methoxyphenyl) in equatorial positions. The molecules of (1) and (2) both display one intramolecular O—H...O hydrogen bond.

scholarly journals 3-Acetyl-1-(3-methylphenyl)thiourea

2012 ◽  
Vol 68 (8) ◽  
pp. o2574-o2574 ◽  
Author(s):  
B. Thimme Gowda ◽  
Sabine Foro ◽  
Sharatha Kumar
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Benzene Ring ◽  
Title Compound ◽  
Side Chain ◽  
Maximum Deviation ◽  
Methyl Groups ◽  
Compound C ◽  
Ring Motif

In the crystal structure of the title compound, C10H12N2OS, the conformation of the two N—H bonds areantito each other. The amide C=O and the C=S are are alsoantito each other. The N—H bond adjacent to the benzene ring issynto them-methyl groups. The dihedral angle between the benzene ring and the side chain [mean plane of atoms C—C(O)N—C—N; maximum deviation 0.029 (2) Å] is 14.30 (7)°. There is an intramolecular N—H...O hydrogen bond generating anS(6) ring motif. In the crystal, the molecules are linkedviaN—H...) hydrogen bonds, forming chains propagating along [001]. The S atom is disordered and was refined using a split model [occupancy ratio 0.56 (4):0.44 (4)].

scholarly journals Crystal structure of 4-chloro-2-{(E)-[(3,4-dimethylphenyl)imino]methyl}phenol

2015 ◽  
Vol 71 (6) ◽  
pp. o416-o416 ◽  
Author(s):  
Muhammad Salim ◽  
Muhammad Nawaz Tahir ◽  
Munawar Ali Munawar ◽  
Muhammad Shahid ◽  
Hazoor Ahmad Shad
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Dihedral Angle ◽  
Title Compound ◽  
Three Dimensional ◽  
Aromatic Rings ◽  
Acta Cryst ◽  
Π Interactions ◽  
Compound C ◽  
Dimensional Network

In the title compound, C15H14ClNO, which is isostructural with its bromo analogue [Tahiret al.(2012).Acta Cryst., E68, o2730], the dihedral angle between the planes of the aromatic rings is 2.71 (7)° and an intramolecular O—H...N hydrogen bond closes anS(6) ring. In the crystal, extremely weak C—H...π interactions link the molecules into a three-dimensional network.

scholarly journals Crystal structure of 9-methacryloylanthracene

2015 ◽  
Vol 71 (4) ◽  
pp. 357-359 ◽  
Author(s):  
Aditya Agrahari ◽  
Patrick O. Wagers ◽  
Steven M. Schildcrout ◽  
John Masnovi ◽  
Wiley J. Youngs
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Dihedral Angle ◽  
Title Compound ◽  
Ring System ◽  
Side Chain ◽  
Weak Hydrogen Bond ◽  
Axis Direction ◽  
Compound C ◽  
Centroid Distance

In the title compound, C18H14O, with systematic name 1-(anthracen-9-yl)-2-methylprop-2-en-1-one, the ketonic C atom lies 0.2030 (16) Å out of the anthryl-ring-system plane. The dihedral angle between the planes of the anthryl and methacryloyl moieties is 88.30 (3)° and the stereochemistry about the Csp2—Csp2bond in the side chain istransoid. In the crystal, the end rings of the anthryl units in adjacent molecules associate in parallel–planar orientations [shortest centroid–centroid distance = 3.6320 (7) Å]. A weak hydrogen bond is observed between an aromatic H atom and the O atom of a molecule displaced by translation in thea-axis direction, forming sheets of parallel-planar anthryl groups packing in this direction.

Redetermination of rifampicin pentahydrate revealing a zwitterionic form of the antibiotic

2012 ◽  
Vol 68 (5) ◽  
pp. o209-o212 ◽  
Author(s):  
Barbara Wicher ◽  
Krystian Pyta ◽  
Piotr Przybylski ◽  
Ewa Tykarska ◽  
Maria Gdaniec
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Amide Group ◽  
Water Molecules ◽  
Acta Cryst ◽  
Oh Groups ◽  
Zwitterionic Form ◽  
The Family

Rifampicin belongs to the family of naphthalenic ansamycin antibiotics. The first crystal structure of rifampicin in the form of the pentahydrate was reported in 1975 [Gadret, Goursolle, Leger & Colleter (1975).Acta Cryst.B31, 1454–1462] with the rifampicin molecule assumed to be neutral. Redetermination of this crystal structure now shows that one of the phenol –OH groups is deprotonated, with the proton transferred to a piperazine N atom, confirming earlier spectroscopic results that indicated a zwitterionic form for the molecule, namely (2S,12Z,14E,16S,17S,18R,19R,20R,21S,22R,23S,24E)-21-acetyloxy-6,9,17,19-tetrahydroxy-23-methoxy-2,4,12,16,18,20,22-heptamethyl-8-[(E)-N-(4-methylpiperazin-4-ium-1-yl)formimidoyl]-1,11-dioxo-1,2-dihydro-2,7-(epoxypentadeca[1,11,13]trienimino)naphtho[2,1-b]furan-5-olate pentahydrate, C43H58N4O12·5H2O. The molecular structure of this antibiotic is stabilized by a system of four intramolecular O—H...O and N—H...N hydrogen bonds. Four of the symmetry-independent water molecules are arrangedviahydrogen bonds into helical chains extending along [100], whereas the fifth water molecule forms only one hydrogen bond, to the amide group O atom. The rifampicin molecules interactviaO—H...O hydrogen bonds, generating chains along [001]. Rifampicin pentahydrate is isostructural with recently reported rifampicin trihydrate methanol disolvate.

Structure of strontium hydroxide octahydrate, Sr(OH)2·8H2O, at 20, 100 and 200 K from neutron diffraction

2005 ◽  
Vol 61 (4) ◽  
pp. 381-386 ◽  
Author(s):  
J. S. Ricci ◽  
R. C. Stevens ◽  
R. K. McMullan ◽  
W. T. Klooster
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Neutron Diffraction ◽  
Diffraction Data ◽  
Double Layers ◽  
Neutron Diffraction Data ◽  
Distorted Octahedra ◽  
Strontium Hydroxide ◽  
Fourfold Axis

The crystal structure of Sr(OH)2·8H2O has been determined at 20, 100 and 200 K from neutron diffraction data. The structure consists of double layers of H2O and OH− ions separated by Sr2+ along the c axis. The Sr2+ ions are eight-coordinated by water O atoms in a square antiprism configuration. Each H2O molecule is engaged in three hydrogen bonds. The OH− ions form chains of acceptor and donor bonds along the fourfold axis with O atoms engaged in four bonds with H2O molecules, such that both non-equivalent O atoms have square-pyramidal environments of five H atoms and the overall bonding configurations of distorted octahedra.

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