Journal ArticleDOI
From weak to strong interactions: A comprehensive analysis of the topological and energetic properties of the electron density distribution involving X–H⋯F–Y systems
TLDR
In this paper, the topological and energetic properties of the electron density distribution ρ(r) of isolated pairwise H⋯F interaction have been theoretically calculated at several geometries and represented against the corresponding internuclear distances.Abstract:
The topological and energetic properties of the electron density distribution ρ(r) of the isolated pairwise H⋯F interaction have been theoretically calculated at several geometries (0.8<d<2.5 A) and represented against the corresponding internuclear distances. From long to short geometries, the results presented here lead to three characteristic regions, which correspond to three different interaction states. While the extreme regions are associated to pure closed-shell (CS) and shared-shell (SS) interactions, the middle one has been related to the redistribution of ρ(r) between those electronic states. The analysis carried out with this system has permitted to associate the transit region between pure CS and SS interactions to internuclear geometries involved in the building of the H–F bonding molecular orbital. A comparative analysis between the formation of this orbital and the behavior of some characteristic ρ(r) properties has indicated their intrinsic correspondence, leading to the definition of a bond degree parameter [BD=HCP/ρCP; HCP and ρCP being the total electron energy density and the electron density value at the H⋯F (3,−1) critical point]. Along with the isolated pairwise H⋯F interaction, 79 X–H⋯F–Y (neutral, positively and negatively charged) complexes have been also theoretically considered and analyzed in terms of relevant topological and energetic properties of ρ(r) found at their H⋯F critical points. In particular, the interaction energies of X–H⋯F–Y pure CS interactions have been estimated by using the bond degree parameter. On the other hand, the [F⋯H⋯F]− proton transfer geometry has been related to the local maximum of the electron kinetic energy density (GCP)max.read more
Citations
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New dinuclear copper(I) metallacycles containing bis-Schiff base ligands fused with two 1,2,4-triazole rings: Synthesis, characterization, molecular structures and theoretical calculations
TL;DR: In this paper, a topological analysis of charge density in the framework of QTAIM shows that there are various noncovalent intramolecular interactions, which control molecular architecture of the complex.
Journal ArticleDOI
Topological analysis of the electron density distribution in perturbed systems. I. Effect of charge on the bond properties of hydrogen fluoride.
TL;DR: The most stable configuration, which corresponds to the unperturbed (F...H) system, shows the highest quantity and the most locally concentrated charge density distribution, along with the largest total electron energy density magnitude, at the interatomic surface.
Journal ArticleDOI
Microsolvation of methylmercury: structures, energies, bonding and NMR constants (199Hg, 13C and 17O)
TL;DR: Thermodynamic stability and the values of NMR constants correlate with the ability of the system to directly coordinate oxygen atoms of water molecules to the mercury atom in methylmercury and with the formation of hydrogen bonds among solvating water molecules.
Journal ArticleDOI
Computational evidence for intramolecular hydrogen bonding and nonbonding X···O interactions in 2'-haloflavonols.
Tânia A. O. Fonseca,Matheus P. Freitas,Rodrigo A. Cormanich,Teodorico C. Ramalho,Cláudio F. Tormena,Roberto Rittner +5 more
TL;DR: The conformer stabilities of 2'-haloflavonols were found to be dictated mainly by a C=O···H–O intramolecular hydrogen bond, but an unusual C–F··· H–O hydrogen-bond and intramolescular C–X···O nonbonding interactions are also present in such compounds.
Journal ArticleDOI
Tuning the interaction energy of hydrogen bonds: the effect of the substituent.
TL;DR: The perturbation in the hydrogen bonding interaction induced by the change of R presents a close similarity with that produced by an external electric field of the same order of magnitude than those found in crystalline solids, indicating that both perturbations should play a significant and similar role on the properties of hydrogen bonds in condensed matter.
References
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Self‐consistent molecular orbital methods 25. Supplementary functions for Gaussian basis sets
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