This work presents an ab initio study on chalcogen–hydride interactions in several binary complexes of chalcogen-containing molecules with HXeH. The geometries, H–Xe stretching frequencies and interaction energies of XCY···HXeH binary complexes are investigated at MP2/aug-cc-pVTZ and CCSD(T)/aug-cc-pVTZ levels of theory, where X = O, S, Se, Te and Y = S, Se, Te. For each XCY···HXeH complex, a chalcogen–hydride bond is formed between the negatively charged hydrogen atom of the HXeH molecule and the most positive electrostatic potential region (σ-hole) on the surface of the interacting atom Y. Upon complex formation, a notable blue shift is found for the H–Xe stretch vibration. This result reveals that there is a stronger H−(XeH)+ ion-pair character in XCY···HXeH complexes than in free HXeH molecule. In order to shed light on the origin of the chalcogen–hydride interactions, molecular electrostatic potential, quantum theory of atoms in molecules and interaction energy decomposition analyses are performed. Cooperative effects between a conventional chalcogen bond and the chalcogen–hydride interaction in OCY···OCY···HXeH complexes are also investigated.
Mehdi D. Esrafili1,Fariba Mohammadian-Sabet2,Mohammad Mehdi Baneshi3
1,2.Laboratory of Theoretical Chemistry, Department of ChemistryUniversity of Maragheh-Maragheh-Iran
3.Department of Environmental Health Engineering, School of Public HealthYasuj University of Medical SciencesYasuj-Iran