Sigma-Hole and Lone-Pair-Hole Site-Based Interactions of Seesaw Tetravalent Chalcogen-Bearing Molecules with Lewis Bases

Mahmoud A A Ibrahim; Rehab R A Saeed; Mohammed N I Shehata; Nayra A M Moussa; Ahmed M Tawfeek; Muhammad Naeem Ahmed; Mohamed K Abd El-Rahman; Tamer Shoeib

doi:10.1021/acsomega.3c03981

Sigma-Hole and Lone-Pair-Hole Site-Based Interactions of Seesaw Tetravalent Chalcogen-Bearing Molecules with Lewis Bases

ACS Omega. 2023 Aug 30;8(36):32828-32837. doi: 10.1021/acsomega.3c03981. eCollection 2023 Sep 12.

Authors

Mahmoud A A Ibrahim^{1

2}, Rehab R A Saeed¹, Mohammed N I Shehata¹, Nayra A M Moussa¹, Ahmed M Tawfeek³, Muhammad Naeem Ahmed⁴, Mohamed K Abd El-Rahman⁵, Tamer Shoeib⁶

Affiliations

¹ Computational Chemistry Laboratory, Chemistry Department, Faculty of Science, Minia University, Minia 61519, Egypt.
² School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban 4000, South Africa.
³ Chemistry Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
⁴ Department of Chemistry, The University of Azad Jammu and Kashmir, Muzaffarabad 13100, Pakistan.
⁵ Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States.
⁶ Department of Chemistry, The American University in Cairo, New Cairo 11835, Egypt.

Abstract

For the first time, sigma (σ)- and lone-pair (lp)-hole site-based interactions of SF₄ and SeF₄ molecules in seesaw geometry with NH₃ and FH Lewis bases were herein comparatively investigated. The obtained findings from the electrostatic potential analysis outlined the emergence of sundry holes on the molecular entity of the SF₄ and SeF₄ molecules, dubbed the σ- and lp-holes. The energetic viewpoint announced splendid negative binding energy values for σ-hole site-based interactions succeeded by lp-hole analogues, which were found to be -9.21 and -0.50 kcal/mol, respectively, for SeF₄···NH₃ complex as a case study. Conspicuously, a proper concurrence between the strength of chalcogen σ-hole site-based interactions and the chalcogen's atomic size was obtained, whereas a reverse pattern was proclaimed for the lp-hole counterparts. Further, a higher preference for the YF₄···NH₃ complexes with elevated negative binding energy was promulgated over the YF₄···FH ones, indicating the eminent role of Lewis basicity. The indications of the quantum theory of atoms in molecules generally asserted the closed-shell nature of all the considered interactions. The observation of symmetry-adapted perturbation theory revealed the substantial contributing role of the electrostatic forces beyond the occurrence of σ-hole site-based interactions. In comparison, the dispersion forces were specified to govern the lp-hole counterparts. Such emerging findings would be a gate for the fruitful forthcoming applications of chalcogen bonding interactions in crystal engineering and biological systems.