Topological reaction sites – very strong chalcogen bonds

Abstract

The analysis of interactions in complexes of S(CN)2, Se(CN)2, SFCl and SeFCl with F(-) and Cl(-) anions is performed here. The sulphur and selenium atoms act in these complexes as Lewis acid centres interacting with fluorine and chlorine anions. The arrangement of sub-units in complexes is in agreement with the σ-hole concept; particularly it is a result of contacts between positive and negative electrostatic potential sites. The interactions in complexes analyzed may be classified as very strong charge assisted chalcogen bonds and they possess numerous characteristics typical for covalent bonds. Even in the case of complexes of SFCl and SeFCl, i.e. SFCl2(-) and SeFCl2(-), the trivalency of the chalcogen atom is observed. The calculations were carried out at the MP2(full)/aug-cc-pVTZ level of approximation, the analyses were performed with the use of the Natural Bond Orbital (NBO) method, the Quantum Theory of 'Atoms in Molecules' (QTAIM) and the Electron Localization Function (ELF) approach. The results obtained by these methods are in agreement giving the consistent picture of the complexes' configurations and their electron charge distribution. The QTAIM and ELF approaches allow us to predict for S(CN)2, Se(CN)2, SFCl and SeFCl molecules the directions of nucleophilic attack. They are in line with the prediction based on the σ-hole concept. The Symmetry Adapted Perturbation Theory (SAPT) approach was also applied.

It Is Important to Compute Intramolecular Hydrogen Bonding in Drug Design?

“…Chalcogen bonds [417,418,419,420,422] (YB) are one of the less studied non-covalent interactions. However, a few articles have been devoted in the literature to the study of intramolecular YBs.…”

Dual functions of Lewis acid and base of Se in F2C=Se and their interplay in F2CSe•••NH3•••HX

“…The σ-hole interaction between the covalently-bonded chalcogen atoms and Lewis bases is also termed as chalcogen bond [7][8][9]. Among it, the chalcogen-chalcogen interaction [18], where both chalcogen atoms individually play the roles of Lewis acid and base, has been widely accepted to be common in crystal engineering and plays a role in organic conductors [19,20].…”

“…The traditional research for the noncovalent interactions mainly focused on hydrogen bonds, but recent interest has also been paid to other types of interactions such as halogen bonds [4][5][6], chalcogen bonds [7][8][9], pnicogen bonds [10][11][12] as well as tetrel bonds [13][14][15]. For the sake of consistency, Politzer and co-authors gave these interactions a name of σ-hole interaction because these group IV-VII atoms provide a σ-hole (a region of electron deficiency in the outer lobe of the p orbital) to interact with Lewis bases [16].…”

Charge‐Assisted Chalcogen Bonds: CSD and DFT Analyses and Biological Implication in Glucosidase Inhibitors

“…The interest in ChB has increased exponentially in the last ten years . It has been recently used in catalysis, molecular recognition, and crystal engineering .…”