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The explicit role of electron exchange in the hydrogen bonded molecular complexes
Author(s) -
Levina Elena O.,
Khrenova Maria G.,
Tsirelson Vladimir G.
Publication year - 2021
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.26507
Subject(s) - electron localization function , chemistry , hydrogen bond , intermolecular force , electron density , covalent bond , delocalized electron , pauli exclusion principle , electron , binding energy , chemical physics , chemical bond , interaction energy , sextuple bond , atoms in molecules , electron pair , computational chemistry , atomic physics , molecule , bond order , bond length , physics , condensed matter physics , quantum mechanics , organic chemistry
We applied a set of advanced bonding descriptors to establish the hidden electron density features and binding energy characteristics of intermolecular DH∙∙∙A hydrogen bonds (OH∙∙∙O, NH∙∙∙O and SH∙∙∙O) in 150 isolated and solvated molecular complexes. The exchange‐correlation and Pauli potentials as well as corresponding local one‐electron forces allowed us to explicitly ascertain how electron exchange defines the bonding picture in the proximity of the H‐bond critical point. The electron density features of DH∙∙∙A interaction are governed by alterations in the electron localization in the H‐bond region displaying itself in the exchange hole. At that, they do not depend on the variations in the exchange hole mobility. The electrostatic interaction mainly defines the energy of H‐bonds of different types, whereas the strengthening/weakening of H‐bonds in complexes with varying substituents depends on the barrier height of the exchange potential near the bond critical point. Energy variations between H‐bonds in isolated and solvated systems are also caused the electron exchange peculiarities as follows from the corresponding potential and the interacting quantum atom analyses complemented by electron delocalization index calculations. Our approach is based on the bonding descriptors associated with the characteristics of the observable electron density and can be recommended for in‐depth studies of non‐covalent bonding.