Estimates of the Energy of Intramolecular Hydrogen Bonds
- 26 August 2006
- journal article
- research article
- Published by American Chemical Society (ACS) in The Journal of Physical Chemistry A
- Vol. 110 (37), 10890-10898
- https://doi.org/10.1021/jp062759o
Abstract
A method for the estimation of the energy of intramolecular hydrogen bonds in conjugated systems existing in a variety of conformations is presented. The method is applied to determine the intramolecular hydrogen bond energy in 3-aminopropenal and 3-aminopropenthial. According to the proposed estimation scheme, the intramolecular H-bond energies are found to be of the order of 5−7 kcal/mol. These results are compared with those obtained by using other estimation schemes as well as with the recent results by other authors. Also, the H-bond energies in dimers and trimers of the two molecules are calculated and compared with the corresponding data for internally hydrogen-bonded monomers. This comparison shows that the bond equalization effect is primarily due to proton donor−proton acceptor proximity. In comparison with intermolecular hydrogen bonds, the rigidity of the chelate skeleton enhances this proximity effect. The same effect can be seen in systems with intermolecular hydrogen bonds, although its magnitude is diminished because of the absence of additional forces which pull the proton donor and proton acceptor groups toward each other. No specific resonance-assisted origin of the intramolecular hydrogen bond energy seems to be needed to elucidate the energetics of these bonds.Keywords
This publication has 25 references indexed in Scilit:
- π‐Electron delocalisation for intramolecular resonance assisted hydrogen bondsJournal of Physical Organic Chemistry, 2003
- Intramolecular Hydrogen Bonds inortho-Substituted Hydroxybenzenes and in 8-Susbtituted 1-Hydroxynaphthalenes: Can a Methyl Group Be an Acceptor of Hydrogen Bonds?The Journal of Physical Chemistry A, 2001
- VMD: Visual molecular dynamicsJournal of Molecular Graphics, 1996
- Origins of Structure and Energetics of van der Waals Clusters from ab Initio CalculationsChemical Reviews, 1994
- Weak interactions between small systems. Models for studying the nature of intermolecular forces and challenging problems for ab initio calculationsChemical Reviews, 1988
- Electronic spectra of .alpha.,.beta.-unsaturated carbonyl compounds. I. An evaluation of increments characteristic of changes in configuration (cis/trans) and conformation (s-cis/s-trans) based on direct observation of the isomerization of enamino aldehydes and ketonesJournal of the American Chemical Society, 1976
- Conformational studies by nuclear magnetic resonance—IV: Restricted rotation in vinylogous thioamidesMagnetic Resonance in Chemistry, 1972
- Conformational studies by nuclear magentic resonance—II: The effect of steric factors on hindered rotation in enamino aldehydes and ketonesMagnetic Resonance in Chemistry, 1972
- Conformational studies by nuclear magnetic resonance. Part I. The barrier to hindered rotation in 4-dimethylaminobut-3-en-2-one around the C–C single bondJournal of the Chemical Society B: Physical Organic, 1971
- Infrared spectra and structure of substituted unsaturated carbonyl compounds—III. Enamino ketones with tertiary amino groupSpectrochimica Acta, 1966