Unexplored ?-hole and ?-hole interactions in (X 2 CY) 2 complexes (X = F, Cl; Y = O, S)

The potentiality of the X 2 CY molecules (X = F, Cl; Y = O, S) to engage in sigma-hole center dot center dot center dot sigma-hole, di- sigma-hole, sigma-hole center dot center dot center dot pi-hole, and pi-hole center dot center dot center dot pi-hole interactions was assessed. In that spirit, potential energy surface (PES) scan was devoted to thoroughly characterize the features of the (X 2 CY) 2 complexes within a series of configurations, including halogen center dot center dot center dot halogen, halogen center dot center dot center dot chalcogen, chalcogen center dot center dot center dot chalcogen, halogen center dot center dot center dot tetrel, chalcogen center dot center dot center dot tetrel, and tetrel center dot center dot center dot tetrel. In most instances, the strength of the inspected interactions declined according to the order: tetrel center dot center dot center dot tetrel (staggered) > tetrel center dot center dot center dot tetrel (eclipsed) > chalcogen center dot center dot center dot tetrel > halogen center dot center dot center dot tetrel > chalcogen center dot center dot center dot chalcogen > halogen center dot center dot center dot chalcogen > halogen center dot center dot center dot halogen configurations. The strength of the explored complexes within tetrel center dot center dot center dot tetrel configurations was found to be dominated further by the contributions of the three planar substituents rather than those of the pi-hole center. Benchmarking of the binding energies emphasized an approximate similarity between the resulted energetic features that were evaluated at the MP2/aug-cc-pVTZ and CCSD/CBS levels of theory. Quantum theory of atoms in molecules (QTAIM) critically unveiled the closed-shell nature of the halogen-, chalcogen-, and tetrel-bonding interactions within the adopted configurations. Symmetry-adapted perturbation theorybased energy decomposition analysis (SAPT-EDA) demonstrated the domination of the sigma-hole interactions by the dispersion forces ( E disp ). In addition to the dominant E disp , preferential contributions of the electrostatic ( E elst ) and induction ( E ind ) forces were detected for the pi-hole bonded complexes within all the scouted configurations. The emerging findings from the current work would be a fruitful underpinning for the forthcoming studies in materials science and crystal engineering. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

This study assessed the potential of X2CY molecules to engage in different types of interactions and characterized the features of the resulting complexes. The findings highlight the significant contribution of planar substituents in tetrel center dot center dot center dot tetrel configurations.