Theoretical Calculations Are a Strong Tool in the Investigation of Strong Intramolecular Hydrogen Bonds

2019 ◽  
pp. 215-251
Author(s):  
Poul Erik Hansen ◽  
Aneta Jezierska ◽  
Jarosław J. Panek ◽  
Jens Spanget‐Larsen
Keyword(s):  
Hydrogen Bonds ◽  
Theoretical Calculations ◽  
Intramolecular Hydrogen Bonds ◽  
Intramolecular Hydrogen

Synthesis of 4-Aryl-3(5)-(2-hydroxyphenyl)pyrazoles by Reaction of Isoflavones and their 4-Thio Analogues with Hydrazine Derivatives

2007 ◽  
Vol 60 (12) ◽  
pp. 905 ◽  
Author(s):  
Albert Lévai ◽  
Artur M. S. Silva ◽  
José A. S. Cavaleiro ◽  
José Elguero ◽  
Ibon Alkorta ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Nmr Spectroscopy ◽  
Hydrogen Bonds ◽  
Hydrazine Hydrate ◽  
1H Nmr ◽  
Theoretical Calculations ◽  
Intramolecular Hydrogen Bonds ◽  
Nmr Study ◽  
Intramolecular Hydrogen ◽  
New Compounds

4-Aryl-3(5)-2-(hydroxyphenyl)pyrazoles have been prepared by the reaction of isoflavones and their 4-thio analogues with hydrazine hydrate and phenylhydrazine in hot pyridine. The reaction mechanism for the formation of these pyrazoles is discussed. All the new compounds have been fully characterized by NMR spectroscopy. In [D6]DMSO, a 1H NMR study allows observation of the presence of both pyrazole annular tautomers, due to the presence of intramolecular hydrogen bonds in each tautomer (OH···N and NH···O). Theoretical calculations have been carried out on tautomers and conformers of compounds 20 (3(5)-(2-hydroxy-4-methoxyphenyl)-5(3)-methyl-4-phenylpyrazole) and 21 (3(5)-(2-hydroxy-4-methoxyphenyl)-4-(2-methoxyphenyl)-5(3)-methylpyrazole), including the absolute shieldings (GIAO/B3 LYP/6–311++G**) of 21.

Intramolecular hydrogen bonds involving organic fluorine in the derivatives of hydrazides: an NMR investigation substantiated by DFT based theoretical calculations

2015 ◽  
Vol 17 (23) ◽  
pp. 15226-15235 ◽  
Author(s):  
Sandeep Kumar Mishra ◽  
N. Suryaprakash
Keyword(s):  
Hydrogen Bonds ◽  
Theoretical Calculations ◽  
Two Dimensional ◽  
Dimensional Solution ◽  
Intramolecular Hydrogen Bonds ◽  
Solution State ◽  
Nmr Techniques ◽  
Intramolecular Hydrogen ◽  
Derivatives Of ◽  
Organic Fluorine

The rare examples of intramolecular hydrogen bonds (HB) of the type the N–H⋯F–C, detected in a low polarity solvent in the derivatives of hydrazides, by utilizing one and two-dimensional solution state multinuclear NMR techniques, are reported.

Organic fluorine involved intramolecular hydrogen bonds in the derivatives of imides: NMR evidence corroborated by DFT based theoretical calculations

RSC Advances ◽  
2015 ◽  
Vol 5 (105) ◽  
pp. 86013-86022 ◽  
Author(s):  
Sandeep Kumar Mishra ◽  
N. Suryaprakash
Keyword(s):  
Hydrogen Bonds ◽  
Theoretical Calculations ◽  
Rare Occurrence ◽  
Intramolecular Hydrogen Bonds ◽  
Multinuclear Nmr ◽  
Intramolecular Hydrogen ◽  
Derivatives Of ◽  
Organic Fluorine

The rare occurrence of intramolecular hydrogen bonds (HBs) of the type N–H⋯F–C is detected in the derivatives of imides in a low polarity solvent by using multi-dimensional and multinuclear NMR experiments.

Controlling emissive properties by intramolecular hydrogen bonds: alkyl and aryl meso‐substituted porphycenes

2021 ◽  
Author(s):  
Jacek Waluk ◽  
Arkadiusz Listkowski ◽  
Natalia Masiera ◽  
Michał Kijak ◽  
Roman Luboradzki ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Intramolecular Hydrogen Bonds ◽  
Intramolecular Hydrogen

Energies of intramolecular hydrogen bonds in some alcohols

1974 ◽  
Vol 20 (3) ◽  
pp. 414-415
Author(s):  
Ya. A. Shuster ◽  
V. A. Granzhan ◽  
P. M. Zaitsev
Keyword(s):  
Hydrogen Bonds ◽  
Intramolecular Hydrogen Bonds ◽  
Intramolecular Hydrogen

Hydrogen bonds in derivatives of N-substituted N’-benzoyl- and N’-(2-chlorobenzoyl)thiourea

1991 ◽  
Vol 56 (4) ◽  
pp. 880-885 ◽  
Author(s):  
Oľga Hritzová ◽  
Dušan Koščík
Keyword(s):  
Hydrogen Bonds ◽  
Spectral Studies ◽  
Intramolecular Hydrogen Bonds ◽  
Tautomeric Forms ◽  
Intramolecular Hydrogen ◽  
Derivatives Of

Intramolecular hydrogen bonds of the N-H···O=C type have been detected in the derivatives of N-substituted N’-benzoyl- and N’-(2-chlorobenzoyl)thiourea on the basis of IR spectral studies. The title compounds can exist in two tautomeric forms.

Spin-spin coupling via intramolecular hydrogen bonds

1985 ◽  
Vol 25 (5) ◽  
pp. 808-810
Author(s):  
L. N. Kurkovskaya ◽  
Yu. M. Chunaev ◽  
N. M. Przhiyalgovskaya
Keyword(s):  
Hydrogen Bonds ◽  
Spin Coupling ◽  
Intramolecular Hydrogen Bonds ◽  
Intramolecular Hydrogen ◽  
Spin Spin Coupling
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