What is hypervalent molecule?

• A hypervalent molecule (the phenomenon is sometimes colloquially known as expanded octet) is a molecule
• that contains one or more main group elements apparently bearing more than eight electrons in their valence shells.
• Phosphorus pentachloride (PCl5),
• sulfur hexafluoride (SF6),
• chlorine trifluoride (ClF3),
• the chlorite (ClO2−) ion, and
• the triiodide (I3−) ion are examples of hypervalent molecules.

Main group elements that form more bonds than would be predicted by the octet rule are called hypervalent compounds, and have what is known as an ' expanded octet,' meaning that there are more than eight electrons around one atom.