https://doi.org/10.1351/goldbook.HT07054
The ability of an atom in a molecular entity to expand its @[email protected] shell beyond the limits of the @[email protected] Hypervalent compounds are common for the second and subsequent row elements in groups 15–18 of the periodic table. A description of the hypervalent bonding implies a transfer of the electrons from the central (hypervalent) atom to the nonbonding molecular orbitals which it forms with (usually more electronegative) @[email protected] A typical example of the hypervalent bond is a linear three-centre, four-electron bond, e.g. that of Fap–P–Fap fragment of PF5.