Unified classification of non-covalent bonds formed by main group elements: a bridge to chemical bonding

Abstract

Using correlation plots of binding energy and electron density at the bond critical point, we investigated the nature of intermolecular non-covalent bonds (D-X···A, where D = O/S/F/Cl/Br/H, mostly, X =...

Aerogen Bond, Halogen Bond, Chalcogen Bond, Pnictogen Bond, Tetrel Bond, Triel Bond ... Why So Many Names?

“…In the weakest, when E···Nu distances are long, effective orbital overlap is impossible. As they become stronger, the E···Nu distance shortens and the A–E covalent bond tends to lengthen, , suggesting increasing n → σ* charge transfer. , Ultimately, the E···Nu interaction may become so strong and the A–E bond so weakened that they are comparable in energy, resulting in a hypervalent structure such as the symmetrical triiodide ion, I 3 – . At this point, the bonding is described as covalent, e.g., 3c-4e bonding for I 3 – .…”

Temperature-dependent work function, thermionic emission and bulk modulus of TiC: a study on the identification of free valence electrons and localized valence electrons and their roles played in carbides

“…In fact, the bonding theory of alloys is based on the assumptions made in terms of free valence electrons and covalent electrons. 31 Recently, Das et al 32 investigated the nature of intermolecular non-covalent bonds by means of correlation between the binding energy and electron density at the bond critical point. By linearly fitting the data of the binding energy and the electron density, the slope of the fitting line could be used to distinguish the ionic, non-covalent and covalent bonds.…”