Probing the halogen bond donation ability of multivalent At-center in AtXn (X = Cl, Br, I; n = 1, 3, 5)⋯H2O/H2S complexes

Abstract

The theoretical calculations on a direct comparison of hypervalent halogen bonds and conventional halogen bonds have been carried out at the MP2/aug-cc-pVTZ-(PP) level, in which multivalent At center acts as Lewis acid to form a collinear and non-coplanar halogen bond with H2O/H2S. This series of complexes is defined as hypervalent halogen bonds complexes, while the halogen bond complex formed by peripheral substituents X and H2O/H2S is defined as a conventional one. The results show that the strength of the hypervalent halogen bonding interaction increases with the increase in the number of halogen atoms added. Moreover, the interaction energy and the topological analysis etc. demonstrate that the multivalent At center exhibits the strongest halogen bond donation ability compared to the traditional halogen atoms.