Basis set and correlation effects on computed hydrogen bond energies of the dimers (AHn)2: AHn=NH3, OH2, and FH

1987 ◽  
Vol 86 (4) ◽  
pp. 2110-2113 ◽  
Author(s):  
Janet E. Del Bene
Keyword(s):  
Hydrogen Bond ◽  
Basis Set ◽  
Correlation Effects ◽  
Bond Energies ◽  
Hydrogen Bond Energies

scholarly journals Intramolecular Hydrogen Bonds in Normal and Sterically Compressed o-Hydroxy Aromatic Aldehydes. Isotope Effects on Chemical Shifts and Hydrogen Bond Strength

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4533 ◽  
Author(s):  
Poul Erik Hansen ◽  
Fadhil S. Kamounah ◽  
Bahjat A. Saeed ◽  
Mark J. MacLachlan ◽  
Jens Spanget-Larsen
Keyword(s):  
Hydrogen Bond ◽  
Chemical Shifts ◽  
Isotope Effects ◽  
Aromatic Aldehydes ◽  
Aldehyde Group ◽  
Basis Set ◽  
Bond Energies ◽  
High Hydrogen ◽  
Intramolecular Hydrogen ◽  
Hydrogen Bond Energies

A number of o-hydroxy aromatic aldehydes have been synthesized to illustrate the effect of steric compression and O···O distances on the intramolecular hydrogen bond and the hydrogen bond energies. Hydrogen bond energies have been calculated using the ‘hb and out’ method using either the MP2 method or the B3LYP functional with the basis set 6-311++G(d,p). However, several compounds cannot be treated this way. Hydrogen bond energies are also determined using electron densities at bond critical points and these results are in good agreement with the results of the ‘hb and out’ model. Two-bond deuterium isotope effects on 13C chemical shifts are suggested as an experimental way to obtain information on hydrogen bond energies as they easily can be measured. Isotope effects on aldehyde proton chemical shifts have also been measured. The former show very good correlation with the hydrogen bond energies and the latter are related to short O···O distances. Short O···O distances can be obtained as the result of short C=C bond lengths, conjugative effects, and steric compression of the aldehyde group. Short O···O distances are in general related to high hydrogen bond energies in these intramolecularly hydrogen-bonded systems of resonance assisted hydrogen bond (RAHB) type.

Hydrogen-bond Energies in the Crystalline State

Nature ◽  
1963 ◽  
Vol 200 (4908) ◽  
pp. 776-777 ◽  
Author(s):  
MANSEL DAVIES ◽  
BRIAN KYBETT
Keyword(s):  
Hydrogen Bond ◽  
Crystalline State ◽  
Bond Energies ◽  
Hydrogen Bond Energies
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