Aerogen Bond, Halogen Bond, Chalcogen Bond, Pnictogen Bond, Tetrel Bond, Triel Bond ... Why So Many Names?
Robin Taylor
Abstract
The nomenclature exemplified in this paper’s title has more terms than necessary. It conceals the often-similar physical natures of the noncovalent interactions that it names, and pointlessly imitates the term used for the most important noncovalent interaction, the hydrogen bond. In doing so, it becomes inconsistent with the naming style of most covalent and several noncovalent interactions. The nomenclature has other shortcomings and has attracted criticism from several quarters. It is suggested here that the simplest alternative nomenclature consists of three terms: σ-hole interaction, π-hole interaction, and p-hole interaction. The first two are well-known and often regarded as implying an electrostatic interaction. Given the Hellmann–Feynman theorem, this expectation is completely satisfied. Additional terms could be used for σ- or p-hole interactions that are almost but not quite hypervalent or dative covalent (“perihypervalent bond” and “pericovalent bond” are suggested). With some exceptions, it is argued that “interaction” should be preferred to “bond”. Effecting a change in nomenclature would be difficult. It is best started by an open and objective exchange of views on the current state of the nomenclature of noncovalent interactions.