scholarly journals Communication: Frequency shifts of an intramolecular hydrogen bond as a measure of intermolecular hydrogen bond strengths

2012 ◽  
Vol 137 (9) ◽  
pp. 091101 ◽  
Author(s):  
Quanli Gu ◽  
Carl Trindle ◽  
J. L. Knee
Keyword(s):  
Hydrogen Bond ◽  
Intramolecular Hydrogen Bond ◽  
Intermolecular Hydrogen Bond ◽  
Frequency Shifts ◽  
Communication Frequency ◽  
Bond Strengths ◽  
Intramolecular Hydrogen

Competing Intramolecular Hydrogen Bond Strengths and Intermolecular Interactions in the 4-Aminobutanol–Water Complex

2018 ◽  
Vol 122 (43) ◽  
pp. 8505-8510 ◽  
Author(s):  
Jenna A. Hohl ◽  
Michael W. Harris ◽  
Nina Strasser ◽  
Anne-Marie Kelterer ◽  
Richard J. Lavrich
Keyword(s):  
Hydrogen Bond ◽  
Intermolecular Interactions ◽  
Intramolecular Hydrogen Bond ◽  
Water Complex ◽  
Bond Strengths ◽  
Intramolecular Hydrogen

scholarly journals Crystal structure of 1-amino-2-oxo-2,5,6,7,8,9-hexahydro-1H-cyclohepta[b]pyridine-3-carbonitrile

2016 ◽  
Vol 72 (9) ◽  
pp. 1239-1241 ◽  
Author(s):  
Galal H. Elgemeie ◽  
Peter G. Jones
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Intramolecular Hydrogen Bond ◽  
Title Compound ◽  
Intermolecular Hydrogen Bond ◽  
Membered Ring ◽  
The Other ◽  
Double Layers ◽  
Compound C ◽  
Intramolecular Hydrogen

In the title compound, C11H13N3O, the seven-membered ring adopts a conformation such that the three atoms not involved in the aromatic plane lie on the same side of that plane. One hydrazinic H atom forms an intramolecular hydrogen bond to the O atom; the other forms a classical intermolecular hydrogen bond N—H...O, which combines with a `weak' Har...O interaction to build up double layers of molecules parallel to thebcplane.

N∊-Benzyloxycarbonyl-Nα-(2-nitrobenzenesulfonyl)-L-lysine

2000 ◽  
Vol 57 (1) ◽  
pp. o48-o49
Author(s):  
José Giraldés ◽  
Mark L. McLaughlin ◽  
Frank R. Fronczek
Keyword(s):  
Hydrogen Bond ◽  
Intramolecular Hydrogen Bond ◽  
Title Compound ◽  
Intermolecular Hydrogen Bond ◽  
Cooh Group ◽  
Extended Conformation ◽  
Compound C ◽  
Intramolecular Hydrogen ◽  
Hydrogen Bonded

The title compound, C20H23N3O8S, is in an extended conformation. The COOH group does not form hydrogen-bonded carboxyl dimers, but forms an intermolecular hydrogen bond with the NCOO carbonyl O atom [O...O 2.666 (2) Å]. The N atom bonded to S is pyramidal, and forms a bifurcated intramolecular hydrogen bond with carboxy and nitro O atoms.

An X-ray crystallographic and density functional theory study of (3Z)-4-(5-ethylsulfonyl-2-hydroxyanilino)pent-3-en-2-one and (3Z)-4-(5-tert-butyl-2-hydroxyanilino)pent-3-en-2-one

2013 ◽  
Vol 69 (3) ◽  
pp. 258-262
Author(s):  
Kate J. Akerman ◽  
Orde Q. Munro
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Intramolecular Hydrogen Bond ◽  
Density Functional ◽  
Intermolecular Hydrogen Bond ◽  
Functional Theory ◽  
One Dimensional ◽  
X Ray ◽  
Intramolecular Hydrogen ◽  
Hydrogen Bonded

The Schiff base enaminones (3Z)-4-(5-ethylsulfonyl-2-hydroxyanilino)pent-3-en-2-one, C13H17NO4S, (I), and (3Z)-4-(5-tert-butyl-2-hydroxyanilino)pent-3-en-2-one, C15H21NO2, (II), were studied by X-ray crystallography and density functional theory (DFT). Although the keto tautomer of these compounds is dominant, the O=C—C=C—N bond lengths are consistent with some electron delocalization and partial enol character. Both (I) and (II) are nonplanar, with the amino–phenol group canted relative to the rest of the molecule; the twist about the N(enamine)—C(aryl) bond leads to dihedral angles of 40.5 (2) and −116.7 (1)° for (I) and (II), respectively. Compound (I) has a bifurcated intramolecular hydrogen bond between the N—H group and the flanking carbonyl and hydroxy O atoms, as well as an intermolecular hydrogen bond, leading to an infinite one-dimensional hydrogen-bonded chain. Compound (II) has one intramolecular hydrogen bond and one intermolecular C=O...H—O hydrogen bond, and consequently also forms a one-dimensional hydrogen-bonded chain. The DFT-calculated structures [in vacuo, B3LYP/6-311G(d,p) level] for the keto tautomers compare favourably with the X-ray crystal structures of (I) and (II), confirming the dominance of the keto tautomer. The simulations indicate that the keto tautomers are 20.55 and 18.86 kJ mol−1lower in energy than the enol tautomers for (I) and (II), respectively.

2-Hydroxy-7-iodocyclohepta-2,4,6-trien-1-one

2007 ◽  
Vol 63 (3) ◽  
pp. o1297-o1299 ◽  
Author(s):  
Kanji Kubo ◽  
Taisuke Matsumoto ◽  
Akira Mori
Keyword(s):  
Hydrogen Bond ◽  
Intramolecular Hydrogen Bond ◽  
Title Compound ◽  
Crystalline State ◽  
Intermolecular Hydrogen Bond ◽  
The Other ◽  
Intramolecular Hydrogen

The title compound, also known as 7-iodotropolone, C7H5IO2, exists in the crystalline state as the 2-hydroxy-7-iodocyclohepta-2,4,6-trien-1-one tautomer and not as 2-hydroxy-3-iodocyclohepta-2,4,6-trien-1-one. There is a bifurcated O—H...O bond with two acceptor O atoms. One of these acceptors is involved in an intramolecular hydrogen bond, and the other in an intermolecular hydrogen bond. There is also a C—H...O interaction in the structure. In addition, there is a C—O...π-cycloheptatriene interaction.

Synthesis and Crystal Structures of 3,6-diacetylated C24 epimeric 20(R)-Ocotillol-Type Saponins

2019 ◽  
Vol 41 (3) ◽  
pp. 452-452
Author(s):  
Juan Liu Juan Liu ◽  
Wen Zhi Wang Wen Zhi Wang ◽  
Jia Zhen Wang Jia Zhen Wang ◽  
Gui Ge Hou Gui Ge Hou ◽  
Qing Guo Meng Qing Guo Meng
Keyword(s):  
Hydrogen Bond ◽  
Single Crystal ◽  
Intramolecular Hydrogen Bond ◽  
1H Nmr ◽  
13C Nmr ◽  
Intermolecular Hydrogen Bond ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Intramolecular Hydrogen ◽  
Optically Pure

(20R,24R)-epoxy-dammar-3β,6α,12β,25-tetraol (1) and (20R,24S)-epoxy- dammar-3β, 6α,12β,25-tetraol (2) have been synthesized from 20(R)-protopanaxatriol with same polarity. In order to obtain optically pure 1 and 2, (20R,24R)-3,6-diacetyl- 20,24-epoxydammar-3β,6α,12β,25-tetraol (3) and (20R,24S)-3,6-diacetyl-20,24- epoxydammar-3β,6α,12β,25-tetraol (4) were designed and prepared to enhance the polarity difference of C24 epimers. Two suitable crystals of 3 and 4 were obtained and their structures were determined by 1H NMR, 13C NMR, HR-MS and X-ray single-crystal diffraction. The results indicated that the C-24 configuration of 3 and 4 are R-form and S-form, respectively. 3 has two intramolecular hydrogen bond. While there is only one in 4 and the crystal stacking displays that it generates a right-handed helically chiral channel viewing from the crystallographic b axis via classical O–H•••O intermolecular hydrogen bond.

scholarly journals Crystal structure of 3-[({2-[bis(2-hydroxybenzyl)amino]ethyl}(2-hydroxybenzyl)amino)methyl]-2-hydroxy-5-methylbenzaldehyde

2014 ◽  
Vol 70 (12) ◽  
pp. 562-565
Author(s):  
Alexandra S. Fonseca ◽  
Adailton J. Bortoluzzi
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Intramolecular Hydrogen Bond ◽  
Intermolecular Hydrogen Bond ◽  
Phenol Group ◽  
The Third ◽  
Graph Set ◽  
Title Molecule ◽  
Intramolecular Hydrogen

The non-symmetric title molecule, C32H34N2O5, is based on a tetrasubstituted ethylenediamine backbone. The molecular structure consists of three hydroxybenzyl groups and one 2-hydroxy-5-methylbenzaldehyde group bonded to the N atoms of the diamine unit. The ethylenediamine skeleton shows a regular extended conformation, while the spatial orientation of the phenol arms is governed by hydrogen bonds. In the 2-hydroxy-5-methylbenzaldehyde group, an intramolecularS(6) O—H...O hydrogen bond is observed between the alcohol and aldehyde functions, and the neighbouring phenol arm participates in an intramolecularS(6) O—H...N hydrogen bond. The third phenol group is involved in a bifurcated intramolecular hydrogen bond with graph-set notationS(6) for O—H...N and O—H...O intramolecular hydrogen bonds between neighbouring amine and phenol arms, respectively. Finally, the fourth phenol group acts as an acceptor in a bifurcated intramolecular hydrogen bond and also acts as donor in an intermolecular hydrogen bond, which connects inversion-related molecules into dimers withR44(8) ring motifs.

scholarly journals C–H⋯F Hydrogen Bond and Integral Intensities of Vinyl C–H Vibtations in Push-Pull β-Dimethylaminotrifluoromethyl Ketone and Its Deuterated Analog

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Sergei Vdovenko ◽  
Igor Gerus ◽  
Elena Fedorenko ◽  
Valery Kukhar
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Dft Calculations ◽  
Intramolecular Hydrogen Bond ◽  
Infrared Spectra ◽  
Intermolecular Hydrogen Bond ◽  
Intermolecular Hydrogen Bonds ◽  
Accurate Analysis ◽  
Deuterated Analog ◽  
Intramolecular Hydrogen

The accurate analysis of infrared spectra (both wavenumbers and intensities) of (E)-4-(dimethylamino)-1,1,1-trifluorobut-3-en-2-one (DMTBN) and (E)-4-(hexadeutero-dimethylamino)-1,1,1-trifluorobut-3-en-2-one (d6-DMTBN) revealed that besides intramolecular hydrogen bond in the (EE) conformer, these enaminoketones form cyclic dimers between the (EZ) and (EE) conformers due to intermolecular hydrogen bonds, namely, O=C and . Evaluation of constant and enthalpy of formation of these H-bonds revealed that O=C bond has greater and more negative than bond (cf. 214.4 M−1, −21.7 kJ M−1dm3, and 16.4 M−1, −6.7 kJ M−1dm3, resp.). Consequently, stronger H-bond ⋯O=C is formed in the first place, whereas weaker H-bond is formed afterward. Moreover, formation of intermolecular hydrogen bond has influence on C–F vibrations, but analysis of this influence must take into account the fact that these vibrations in some cases are coupled with . True enthalpy of the equilibrium (EZ)⇌(EE) is positive (25.3 kJ M−1dm3), thus confirming results of DFT calculations, according to which the (EZ) conformer is more stable than the (EE) one.

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