Hexafluoro

Hexafluoro is a chemical nomenclature prefix indicating six fluorine atoms or substituents in a molecule. It is built from the Greek/Latin roots hexa- meaning six and fluoro- referring to fluorine. The term appears in inorganic and organofluorine chemistry to describe compounds where six fluorine atoms are bound to a central atom or serve as substituents.

Common examples include sulfur hexafluoride (SF6), where six fluorine atoms surround a sulfur center; hexafluorobenzene (C6F6), a perfluorinated aromatic compound; and various hexafluorometallate or hexafluoroanion species such as hexafluorophosphate (PF6−) and hexafluoroantimonate (SbF6−) that act as counterions in salts and ionic liquids. Hexafluoroaluminate (AlF6)3− is another widely encountered hexafluoroanion in solid-state and solution chemistry. The prefix is also used in other fluorinated units, where six fluorine atoms are part of the molecular framework.

Properties and behavior of hexafluoro compounds tend to reflect the strength of carbon–fluorine or metal–fluorine bonds and the high electronegativity of fluorine. Many such compounds are chemically and thermally robust and exhibit high stability or inertness under standard conditions, though some are reactive under strong Lewis acidic conditions or upon hydrolysis (for example, PF6− can produce fluoride salts and hydrofluoric acid in the presence of water).

Applications vary by compound but can include use as insulating gases (SF6), as stable counterions in salts and electrolytes (PF6−, SbF6−), and as building blocks or solvents in specialized fluorination chemistry. Environmental and safety considerations, particularly for greenhouse gases like SF6, influence handling and regulatory controls.