Three-center four-electron bond

A three-center four-electron bond is a type of chemical bonding that involves three atoms and shares four electrons among them. This bonding scenario is commonly found in certain molecular structures, particularly in electron-deficient systems or while describing certain types of stable intermediates. In a typical covalent bond, two atoms share a pair of electrons, forming a two-center two-electron bond. The three-center four-electron bond, however, is characterized by the sharing of electrons across three atomic centers.