Osme Bonds in Molecular Crystals: Structural Insights, Substituent Effects, and Energetic Features

Abstract

The metal-centered noncovalent interactions known as Osme bonds (OmBs) which involve group 8 elements have become the subject of interest because of their significance in supramolecular chemistry as well as catalysis and crystal engineering. We investigate how osmium tetroxide (OsO₄) complexes form metal-centered noncovalent OmBs bonds with anionic donors such as fluoride and chloride, while neutral donors such as amines and N-oxides also contribute to these interactions. The Cambridge Structural Database (CSD) systematic survey details how common these interactions are and describes their geometric properties. The nature of OmBs becomes clearer through density functional theory (DFT) calculations which demonstrate their partially covalent character while showing how substituent effects can modulate these properties. Binding energies show strong correlations with both molecular electrostatic potential (MEP) and Hammett’s σ_p constants indicating that electrostatic forces drive OmBs yet orbital contributions maintain importance. Our research work enhances knowledge about OmBs and their function in molecular construction and reaction processes, which expands the field of metal-based noncovalent interactions within supramolecular chemistry.