Fluorine perchlorate - Misplaced Pages

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 and has a penetrating odor.

Synthesis

One synthesis uses fluorine and perchloric acid, though the action of ClF₅ on water is another method.

{\ce {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.

{\ce {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:

{\ce {FOClO3 + 2I^- -> ClO4^- + F^- + I2}}

FClO₄ can also react with tetrafluoroethylene:

{\ce {CF2=CF2 + FOClO3 -> CF3CF2OClO3}}

It may be a radical addition reaction.

References

Breazeale, J. D.; MacLaren, R. O.. Thermochemistry of oxygen-fluorine bonding, United Technology Center, Sunnyvale, CA, 1963. Accession Number: AD0402889. Retrieved online from on 2009-05-21.
Pradyot Patnaik. A comprehensive guide to the hazardous properties of chemical substances, 3rd ed., Wiley-Interscience, 2007. ISBN 0-471-71458-5
Robert Alan Lewis. Lewis' dictionary of toxicology, CRC Press, 1998, p. 508. ISBN 1-56670-223-2
Rohrback, G. H.; Cady, G. H. (1947). "The Preparation of Fluorine Perchlorate from Fluorine and Perchloric Acid". Journal of the American Chemical Society. 69 (3): 677–678. doi:10.1021/ja01195a063.
Schack, C. J.; Christe, K. O. (1979). "Reactions of fluorine perchlorate with fluorocarbons and the polarity of the oxygen-fluorine bond in covalent hypofluorites". Inorganic Chemistry. 18 (9): 2619–2620. doi:10.1021/ic50199a056.
Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
Schack, Carl J.; Christe, Karl O. (1979). "Reactions of fluorine perchlorate with fluorocarbons and the polarity of the oxygen-fluorine bond in covalent hypofluorites". Inorganic Chemistry. 18 (9): 2619. doi:10.1021/ic50199a056.