Premium
Fluorine as a Lewis acid: A symmetry‐adapted perturbation theory based on density functional theory and interacting quantum atoms study of noncovalent interactions in the NCF⋯NH 3 complex
Author(s) -
Orangi Nasim,
Eskandari Kiamars
Publication year - 2020
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.26202
Subject(s) - non covalent interactions , chemistry , halogen , density functional theory , fluorine , halogen bond , lewis acids and bases , perturbation theory (quantum mechanics) , van der waals force , computational chemistry , crystallography , chemical physics , hydrogen bond , molecule , physics , quantum mechanics , organic chemistry , alkyl , catalysis
Different computational methods are used to investigate the nature of interaction in the NCF⋯NH 3 model complex, in which the fluorine atom acts as a Lewis acid and forms a noncovalent bond with the ammonia (Lewis base). Symmetry‐adapted perturbation theory based on density functional theory (SAPT(DFT)) indicates that the noncovalent interaction in the NCF⋯NH 3 complex is mainly electrostatics. However, dispersion and induction terms also play important roles. Although fluorine noncovalent interactions are typically classified as halogen bonds, they are somewhat different from the well‐known halogen bonds of iodine, bromine, and chlorine. The halogen bonds of NCCl⋯NH 3 and NCBr⋯NH 3 are directional and the C X N (X = Cl or Br) angle tends to be linear. In contrast, the fluorine interaction in NCF⋯NH 3 is not directional; the interaction energy shows no sensitivity to the angular ( C F N ) distortions, and the energy profile is flat over a wide angular range (from 180° to about 140° ). However, for the angles less than 130° , the energy curve shows a clear angular dependence and the interaction between NCF and NH 3 becomes stronger as the C F N angle decreases. It seems that at the tighter angles, a tetrel‐bonded NCF⋯NH 3 complex is preferred. Moreover, interacting quantum atoms (IQA) analysis shows that the competition between different intra‐atomic and interatomic interactions determines the geometry of NCF⋯NH 3 complex.