Osme Bond: Geometric and Energetic Features in the Adducts between OsO₄ and Lewis Bases

Adducts between OsO₄ and Lewis bases exert a role in important oxidation processes such as epoxidation and dihydroxylation. It has been shown that the attractive interaction driving the formation of these adducts is a σ-hole bond involving the metal as the electrophilic species; the term Osme Bond (OmB) was proposed for designating it. Here some new adducts between OsO₄ and various bases have been characterized through single crystal x-ray diffraction (XRD) and computational studies (density functional theory, DFT), confirming the existence of a robust correlation between σ-hole interaction energy and deformation of the tetrahedral geometry of OsO₄. Also, some adducts formed by RuO₄ with nucleophiles were investigated computationally.