Iodine pentafluoride (IF5)

Structure and bonding

The molecule adopts a square pyramidal geometry that can be rationalized by VSEPR theory (AX5E): five bonding pairs and one lone pair on iodine. This arrangement gives rise to one axial and four equatorial I–F positions, with modest differences in bond environment between them. The bonding is predominantly covalent with significant polarization because fluorine is strongly electronegative.

Preparation and reactions

IF5 is commonly prepared by direct combination of elemental iodine and fluorine under controlled conditions. It is a powerful fluorinating and oxidizing reagent: it will add fluorine to or oxidize many inorganic and organic substrates. The compound hydrolyzes readily upon contact with water, producing oxyiodine species (for example iodic acid) and hydrogen fluoride, so it must be handled with care.

Uses and examples

In research and synthetic chemistry IF5 is employed as a fluorinating agent when milder reagents are ineffective. It has been used to introduce fluorine atoms into halogenated aromatics and in specialized inorganic fluorination procedures. Because of its reactivity it is typically used on small scale in well-ventilated fume hoods and with appropriate protective equipment.

Safety and handling

• Corrosivity: IF5 attacks glass and many metals unless materials are compatible.
• Hazards: Hydrolysis produces hydrogen fluoride (HF), which is highly toxic and corrosive.
• Storage and transfer are done under inert atmosphere; emergency measures focus on HF exposure and containment.

For further technical details, analytical data, and precautions see general chemical references and safety databases: structure and properties, preparation, and specialized safety resources handling guidance.