Fluorine perchlorate

Not to be confused with perchloryl fluoride.

Fluorine perchlorate, also called perchloryl hypofluorite is the rarely encountered chemical compound of fluorine, chlorine, and oxygen with the chemical formula ClO
₄F or FOClO
₃. It is an extremely unstable gas that explodes spontaneously^[2] and has a penetrating odor.^[3]

Fluorine perchlorate

Names
IUPAC name Perchloryl hypofluorite
Other names Fluorine perchlorate
Identifiers
CAS Number	10049-03-3 Y
3D model (JSmol)	Interactive image
ChemSpider	10326178 N
PubChem CID	13022374
UNII	M5BON9S68S N
CompTox Dashboard (EPA)	DTXSID40515441
InChI InChI=1S/ClFO4/c2-6-1(3,4)5 N Key: DRFVFUCINMEBEQ-UHFFFAOYSA-N N InChI=1/ClFO4/c2-6-1(3,4)5 Key: DRFVFUCINMEBEQ-UHFFFAOYAO
SMILES FOCl(O)(O)O
Properties
Chemical formula	FClO 4
Melting point	−167.3 °C (−269.1 °F; 105.8 K)
Boiling point	−16 °C (3 °F; 257 K)
Thermochemistry
Std enthalpy of formation (ΔfH⦵298)	9 kcal/mol[1]
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Highly explosive gas
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Synthesis

One synthesis uses fluorine and perchloric acid,^[4] though the action of ClF₅ on water is another method.^{[citation needed]}

F₂ + HClO₄ → FClO₄ + HF

Another method of synthesis involves the thermal decomposition of tetrafluoroammonium perchlorate, NF
₄ClO
₄, which yields very pure FClO
₄ that may be manipulated and frozen without explosions.^[5]

NF₄ClO₄ → NF₃ + FClO₄

Structure

Fluorine perchlorate is not analogous to perchloric acid because the fluorine atom is more electronegative than oxygen. It contains an oxygen atom in a rare oxidation state of 0 due to the electronegativity of oxygen, which is higher than that of chlorine but lower than that of fluorine.

Safety

FClO₄ has a very dangerous and unpredictable series of reactions associated with it, as a covalent perchlorate (chlorine in the +7 oxidation state) and a compound featuring a very sensitive O-F single bond. Small amounts of reducing agents, such as organic compounds, can trigger explosive detonation. Products of these decomposition reactions could include oxygen halides, interhalogen compounds, and other hazardous substances.

Accidental synthesis is possible if precursors are carelessly mixed. Like similar covalent fluorides and perchlorates, it needs to be handled with extreme caution.

Reaction

FClO₄ is a strong oxidant and it reacts with the iodide ion:

FOClO₃ + 2 I⁻ → ClO−4 + F⁻ + I₂

FClO₄ can also react with tetrafluoroethylene:^[6]

CF₂=CF₂ + FOClO₃ → CF₃CF₂OClO₃

It may be a radical addition reaction.^[7]