The crystal structure of the hemihydrochloride of coccinellin, the defensive N-oxide alkaloid of the beetle Coccinella Septempunctata, a case of symmetrical hydrogen bonding

1972 ◽  
pp. 626 ◽  
Author(s):  
Rolf Karlsson ◽  
Danielle Losman
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Coccinella Septempunctata

A neutron diffraction study of hydrogen bonding in the deuterium (hydrogen) L-arginine phosphate monohydrate

1997 ◽  
Vol 212 (3) ◽  
Author(s):  
Z. Cheng ◽  
Y. Cheng ◽  
L. Guo ◽  
D. Xu
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Neutron Diffraction ◽  
Diffraction Study ◽  
Title Compound ◽  
Neutron Diffraction Study ◽  
Chemical Formula

AbstractThe crystal structure of the title compound D(H)LAP with chemical formula (D

scholarly journals Hydrogen bonding versus packing effects in the crystal structure of 3-((1R,2S)-1-methylpyrrolidin-1-ium-2-yl)pyridin-1-ium tetraiodidozincate(II), C10H16I4ZnN2

2020 ◽  
Vol 235 (4) ◽  
pp. 959-962
Author(s):  
Guido J. Reiss ◽  
Alena Sergeeva
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Packing Effects

AbstractC10H16I4ZnN2, monoclinic, P21 (no. 4), a = 7.3340(1) Å, b = 14.4781(3) Å, c = 8.6768(2) Å, β = 94.919(2)°, V = 917.93(3) Å3, Z = 2, Rgt(F) = 0.0165, wRref(F2) = 0.0397, T = 110 K.

scholarly journals Exploring the Structural Chemistry of Pyrophosphoramides: N,N′,N″,N‴-Tetraisopropylpyrophosphoramide

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 149-163
Author(s):  
Duncan Micallef ◽  
Liana Vella-Zarb ◽  
Ulrich Baisch
Keyword(s):  
Crystal Structure ◽  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Hydrogen Bonding ◽  
Nmr Spectroscopy ◽  
Ir Spectroscopy ◽  
Room Temperature ◽  
Intermolecular Hydrogen Bonding ◽  
X Ray Diffraction ◽  
X Ray

N,N′,N″,N‴-Tetraisopropylpyrophosphoramide 1 is a pyrophosphoramide with documented butyrylcholinesterase inhibition, a property shared with the more widely studied octamethylphosphoramide (Schradan). Unlike Schradan, 1 is a solid at room temperature making it one of a few known pyrophosphoramide solids. The crystal structure of 1 was determined by single-crystal X-ray diffraction and compared with that of other previously described solid pyrophosphoramides. The pyrophosphoramide discussed in this study was synthesised by reacting iso-propyl amine with pyrophosphoryl tetrachloride under anhydrous conditions. A unique supramolecular motif was observed when compared with previously published pyrophosphoramide structures having two different intermolecular hydrogen bonding synthons. Furthermore, the potential of a wider variety of supramolecular structures in which similar pyrophosphoramides can crystallise was recognised. Proton (1H) and Phosphorus 31 (31P) Nuclear Magnetic Resonance (NMR) spectroscopy, infrared (IR) spectroscopy, mass spectrometry (MS) were carried out to complete the analysis of the compound.

scholarly journals Theoretical Study of the Structures of 4-(2,3,5,6-Tetrafluoropyridyl)Diphenylphosphine Oxide and Tris(Pentafluorophenyl)Phosphine Oxide: Why Does the Crystal Structure of (Tetrafluoropyridyl)Diphenylphosphine Oxide Have Two Different P=O Bond Lengths?

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2778
Author(s):  
Joseph R. Lane ◽  
Graham C. Saunders
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Phosphine Oxide ◽  
Density Functional ◽  
Lone Pair ◽  
Diphenylphosphine Oxide ◽  
Functional Theory ◽  
Weak Hydrogen Bonding ◽  
Independent Molecules ◽  
The Difference

The crystal structure of 4-(2,3,5,6-tetrafluoropyridyl)diphenylphosphine oxide (1) contains two independent molecules in the asymmetric unit. Although the molecules are virtually identical in all other aspects, the P=O bond distances differ by ca. 0.02 Å. In contrast, although tris(pentafluorophenyl)phosphine oxide (2) has a similar crystal structure, the P=O bond distances of the two independent molecules are identical. To investigate the reason for the difference, a density functional theory study was undertaken. Both structures comprise chains of molecules. The attraction between molecules of 1, which comprises lone pair–π, weak hydrogen bonding and C–H∙∙∙arene interactions, has energies of 70 and 71 kJ mol−1. The attraction between molecules of 2 comprises two lone pair–π interactions, and has energies of 99 and 100 kJ mol−1. There is weak hydrogen bonding between molecules of adjacent chains involving the oxygen atom of 1. For one molecule, this interaction is with a symmetry independent molecule, whereas for the other, it also occurs with a symmetry related molecule. This provides a reason for the difference in P=O distance. This interaction is not possible for 2, and so there is no difference between the P=O distances of 2.

2,4,6-Trimethylpyridine-3,5-dicarbonitrile

2006 ◽  
Vol 62 (7) ◽  
pp. o2765-o2767
Author(s):  
Hong-Li Wang ◽  
Bin Zhang ◽  
Yi Dai
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Title Compound ◽  
Asymmetric Unit ◽  
Compound C ◽  
Hydrogen Bonding Interactions

The title compound, C10H9N3, is essently planar, except for the methyl H atoms. The asymmetric unit consists of two molecules. In the crystal structure, weak intramolecular C—H...N hydrogen-bonding interactions occur, linking the molecules into chains propagating along the a axis.

Hydrogen bonding of catechol groups in the crystal structure of dihydrocaffeic acid

2013 ◽  
Vol 54 (2) ◽  
pp. 368-372
Author(s):  
T. N. Drebushchak ◽  
E. V. Boldyreva ◽  
K. Fucke
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding
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