Charge-Assisted Intramolecular Hydrogen Bonds in Disubstituted Cyclohexane Derivatives
- 10 November 2011
- journal article
- research article
- Published by American Chemical Society (ACS) in The Journal of Physical Chemistry A
- Vol. 115 (48), 14069-14077
- https://doi.org/10.1021/jp206193a
Abstract
In this paper, the N+–H···N, N+–H···O, and O–H···O– charge-assisted intramolecular hydrogen bonds (CAHBs) are investigated using different theoretical approaches. Monocharged cyclohexyldiamines (CHDA), aminocyclohexanols (ACHO), and cyclohexanediols (CHDO) are used as model compounds. Geometry optimizations at the MP2/aug-cc-pVDZ level are used to find the equilibrium structures for all possible H-bonded conformers. CAHBs are characterized geometrically and spectroscopically, and their energy is evaluated by means of homodesmic reactions. By comparison with the neutral forms, the presence of the charge is found to have a deep influence on the geometric and energetic H-bond parameters. In addition, these parameters are strongly dependent on the type of the groups involved as well as on their relative position in the cyclohexyl ring. For the systems under study, the H-bond energies vary from −23 to −113 kJ mol–1, being classified from moderate to strong H-bonds. These H-bonds are also characterized by the application of the NBO and AIM theories. NBO analysis reveals that the energy corresponding to the charge transfer between the lone-pairs of the electron donor group and the antibonding orbitals of the acceptor group represents an important contribution in the H-bond stabilization. From the application of the AIM theory it is possible to see that these H-bonds possess some covalence which varies according to the type and relative position of the intervenient groups.Keywords
This publication has 51 references indexed in Scilit:
- Defining the hydrogen bond: An account (IUPAC Technical Report)Pure and Applied Chemistry, 2011
- Intramolecular Hydrogen Bond Energy in Polyhydroxy Systems: A Critical Comparison of Molecular Tailoring and Isodesmic ApproachesThe Journal of Physical Chemistry A, 2007
- On the nature of hydrogen bonds: an overview on computational studies and a word about patternsPhysical Chemistry Chemical Physics, 2007
- Estimation of Intramolecular Hydrogen Bond Energy via Molecular Tailoring ApproachThe Journal of Physical Chemistry A, 2006
- Design of crystalline molecular networks with charge-assisted hydrogen bondsChemical Communications, 2005
- Acidities in Cyclohexanediols Enhanced by Intramolecular Hydrogen BondsJournal of the American Chemical Society, 2004
- Protonation Thermochemistry of α,ω-Alkyldiamines in the Gas Phase: A Theoretical StudyThe Journal of Physical Chemistry A, 2001
- Natural steric analysis of internal rotation barriersInternational Journal of Quantum Chemistry, 1999
- Low-Barrier Hydrogen Bonds and Enzymic CatalysisScience, 1994
- The Dependence of Interatomic Distance on Single Bond-Double Bond Resonance1Journal of the American Chemical Society, 1935