Perchloryl fluoride is a reactive gas with the

chemical formula In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, ...

. It has a characteristic sweet odor that resembles gasoline and kerosene. It is toxic and is a powerful

oxidizing Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a d ...

and

fluorinating agent In chemistry, halogenation is a chemical reaction that entails the introduction of one or more halogens into a compound. Halide-containing compounds are pervasive, making this type of transformation important, e.g. in the production of polymers, ...

. It is the acid fluoride of

perchloric acid Perchloric acid is a mineral acid with the formula H Cl O4. Usually found as an aqueous solution, this colorless compound is a stronger acid than sulfuric acid, nitric acid and hydrochloric acid. It is a powerful oxidizer when hot, but aqueous sol ...

. In spite of its small enthalpy of formation (Δ''H''_f^° = −5.2 kcal/mol), it is kinetically stable, decomposing only at 400 °C. It is quite reactive towards reducing agents and anions, however, with the chlorine atom acting as an

electrophile In chemistry, an electrophile is a chemical species that forms bonds with nucleophiles by accepting an electron pair. Because electrophiles accept electrons, they are Lewis acids. Most electrophiles are positively charged, have an atom that carries ...

. It reacts explosively with reducing agents such as metal

amide In organic chemistry, an amide, also known as an organic amide or a carboxamide, is a compound with the general formula , where R, R', and R″ represent organic groups or hydrogen atoms. The amide group is called a peptide bond when it is ...

s, metals,

hydride In chemistry, a hydride is formally the anion of hydrogen( H−). The term is applied loosely. At one extreme, all compounds containing covalently bound H atoms are called hydrides: water (H2O) is a hydride of oxygen, ammonia is a hydride of ...

s, etc. Its hydrolysis in water occurs very slowly, unlike that of

chloryl fluoride Chloryl fluoride is the chemical compound with the formula ClO2F. It is commonly encountered as side-product in reactions of chlorine fluorides with oxygen sources. It is the acyl fluoride of chloric acid. Preparation ClO2F was first reported by ...

Synthesis and chemistry

Perchloryl fluoride is produced primarily by the fluorination of

perchlorate A perchlorate is a chemical compound containing the perchlorate ion, . The majority of perchlorates are commercially produced salts. They are mainly used as oxidizers for pyrotechnic devices and to control static electricity in food packaging. Per ...

Antimony pentafluoride Antimony pentafluoride is the inorganic compound with the formula Sb F5. This colourless, viscous liquid is a valuable Lewis acid and a component of the superacid fluoroantimonic acid, formed when mixing liquid HF with liquid SbF5 in a 2:1 ratio. ...

is a commonly used fluorinating agent: : + 3 HF + 2 → + + 2 reacts with

alcohol Alcohol most commonly refers to: * Alcohol (chemistry), an organic compound in which a hydroxyl group is bound to a carbon atom * Alcohol (drug), an intoxicant found in alcoholic drinks Alcohol may also refer to: Chemicals * Ethanol, one of sev ...

s to produce

alkyl In organic chemistry, an alkyl group is an alkane missing one hydrogen. The term ''alkyl'' is intentionally unspecific to include many possible substitutions. An acyclic alkyl has the general formula of . A cycloalkyl is derived from a cycloalk ...

perchlorates, which are extremely shock-sensitive explosives. In the presence of a Lewis acid, it can be used for introducing the group into aromatic rings via

electrophilic aromatic substitution Electrophilic aromatic substitution is an organic reaction in which an atom that is attached to an aromatic system (usually hydrogen) is replaced by an electrophile. Some of the most important electrophilic aromatic substitutions are aromatic ni ...

Applications

Perchloryl fluoride is used in organic chemistry as a mild fluorinating agent. It was the first industrially relevant

electrophilic In chemistry, an electrophile is a chemical species that forms bonds with nucleophiles by accepting an electron pair. Because electrophiles accept electrons, they are Lewis acids. Most electrophiles are positively charged, have an atom that carri ...

fluorinating agent, used since the 1960s for producing fluorinated

steroid A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and a ...

s. In the presence of aluminum trichloride, it has also been used as an electrophilic perchlorylation reagent for aromatic compounds. Perchloryl fluoride was investigated as a high performance

liquid rocket fuel The highest specific impulse chemical rockets use liquid propellants (liquid-propellant rockets). They can consist of a single chemical (a monopropellant) or a mix of two chemicals, called bipropellants. Bipropellants can further be divided into ...

oxidizer. In comparison with

chlorine pentafluoride Chlorine pentafluoride is an interhalogen compound with formula ClF5. This colourless gas is a strong oxidant that was once a candidate oxidizer for rockets. The molecule adopts a square pyramidal structure with C4v symmetry, as confirmed by ...

and

bromine pentafluoride Bromine pentafluoride, Br F5, is an interhalogen compound and a fluoride of bromine. It is a strong fluorinating agent. BrF5 finds use in oxygen isotope analysis. Laser ablation of solid silicates in the presence of BrF5 releases O2 for subsequ ...

, it has significantly lower

specific impulse Specific impulse (usually abbreviated ) is a measure of how efficiently a reaction mass engine (a rocket using propellant or a jet engine using fuel) creates thrust. For engines whose reaction mass is only the fuel they carry, specific impulse i ...

, but does not tend to corrode tanks. It does not require cryogenic storage. Rocket fuel chemist

John Drury Clark John Drury Clark, Ph.D. (August 15, 1907 – July 6, 1988) was an American rocket fuel developer, chemist, and science fiction writer. He was instrumental in the revival of interest in Robert E. Howard's '' Conan'' stories and influenced the writ ...

reported in his book ''Ignition!'' that perchloryl fluoride is completely miscible with all-halogen oxidizers such as

chlorine trifluoride Chlorine trifluoride is an interhalogen compound with the formula ClF3. This colorless, poisonous, corrosive, and extremely reactive gas condenses to a pale-greenish yellow liquid, the form in which it is most often sold (pressurized at room temp ...

and

, and such a mixture provides the needed oxygen to properly burn carbon-containing fuels. It can also be used in flame photometry as an excitation source.

Safety

Perchloryl fluoride is toxic, with a TLV of 3 ppm. It is a strong lung- and eye-irritant capable of producing burns on exposed skin. Its

IDLH The term immediately dangerous to life or health (IDLH) is defined by the US National Institute for Occupational Safety and Health (NIOSH) as exposure to airborne contaminants that is "likely to cause death or immediate or delayed permanent advers ...

level is 100 ppm. Symptoms of exposure include dizziness, headaches, syncope, and

cyanosis Cyanosis is the change of body tissue color to a bluish-purple hue as a result of having decreased amounts of oxygen bound to the hemoglobin in the red blood cells of the capillary bed. Body tissues that show cyanosis are usually in locations ...

. Exposure to toxic levels causes severe respiratory tract inflammation and

pulmonary edema Pulmonary edema, also known as pulmonary congestion, is excessive edema, liquid accumulation in the parenchyma, tissue and pulmonary alveolus, air spaces (usually alveoli) of the lungs. It leads to impaired gas exchange and may cause hypoxemia an ...

References

{{DEFAULTSORT:Perchloryl Fluoride Inorganic chlorine compounds Oxyfluorides Rocket oxidizers Fluorinating agents Perchloryl compounds Sweet-smelling chemicals