Attraction between electrophilic caps: A counterintuitive case of noncovalent interactions. Issue 9 (3rd October 2018)

• Record Type: Journal Article
• Authors: Wang, Changwei; Danovich, David; Shaik, Sason; Wu, Wei; Mo, Yirong
• Is Part Of: Journal of computational chemistry. Volume 40:Issue 9(2019)
• Page Start: 1015
• Page End: 1022
• Publication Date: 2018-10-03
• Subjects: noncovalent interaction -- electrostatic attraction -- σ‐hole -- energy decomposition analysis -- valence bond theory; Chemistry -- Data processing -- Periodicals; 542.85
• DOI: 10.1002/jcc.25566
• Languages: English
• ISSNs: 0192-8651

Abstract

Abstract : Intermolecular attractive interaction between electrophilic sites is a counterintuitive phenomenon, as the electrostatic interaction therein is repulsive and destabilizing. Here, we confirm this phenomenon in four representative complexes, using state‐of‐the‐art quantum mechanical methods. By employing the block‐localized wavefunction (BLW) method, which can turn off intermolecular charge transfer interactions, we profoundly demonstrated the significance of charge transfer interactions in these seemingly counterintuitive complexes. Indeed, after being "turned off" the intermolecular charge transfer interaction in, for example, the FNSi···BrF complex, the originally attractive intermolecular interaction turns to be repulsive. The energy decomposition approach based on the BLW method (BLW‐ED) can partition the overall stability gained on the formation of intermolecular noncovalent interaction into several physically meaningful components. According to the BLW‐ED analysis, the electrostatic repulsion in these counterintuitive cases is overwhelmed by the stabilizing polarization, dispersion interaction, and most importantly, the charge transfer interaction, resulting in the eventual counterintuitive overall attraction. The present study suggests that, predicting bonding sites of noncovalent interactions using only the "hole" concept may be not universally sufficient, because other significant stabilizing factors will contribute to the stability and sometimes, play even bigger roles than the electrostatic interaction and consequently govern the complex structures. © 2018 Wiley Periodicals, Inc. Abstract : Computations based on the block‐localized wavefunction (BLW) method show that the charge transfer interactions are largely responsible for the intermolecular attraction between electrophilic sites which otherwise seems counterintuitive. If the intermolecular charge transfer interaction in the FNSi···BrF complex is "turned off, " the originally attractive intermolecular interaction turns to be repulsive. The subsequent BLW energy decomposition analyses indicate that the electrostatic repulsion in other similar counterintuitive cases is overwhelmed by the stabilizing polarization, dispersion interaction, and most importantly, the charge transfer interaction.