Perchloryl fluoride
Encyclopedia
Perchloryl fluoride is a reactive gas with the chemical formula
. It has a characteristic sweet odor that resembles gasoline and kerosene. It is toxic and is a powerful oxidizing
and fluorinating agent. It is the acid fluoride of perchloric acid
.
In spite of its small enthalpy of formation (ΔHfO = −5.7), 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
. It reacts explosively with reducing agents such as amide
s, metals, hydride
s, etc.
s. Antimony pentafluoride
is a commonly-used fluorinating agent:
reacts with alcohol
s to produce alkyl perchlorates, which are extremely shock-sensitive explosives. Using Friedel-Crafts catalysts, it can be used for introducing the group into aromatic rings via electrophilic aromatic substitution
.
fluorinating agent, used since the 1960s for producing fluorinated steroid
s.
Perchloryl fluoride was investigated as a high performance liquid rocket fuel oxidizer. In comparison with chlorine pentafluoride
and bromine pentafluoride
, it has significantly lower specific impulse
, but does not tend to corrode tanks. It does not require cryogenic storage.
It can also be used in flame photometry
as an excitation source.
of 3 ppm. It is a strong lung- and eye-irritant capable of producing burns on exposed skin. Its IDLH
level is 385 ppm. Symptoms of exposure include dizziness, headaches, syncope
, and cyanosis
. Exposure to toxic levels causes severe respiratory tract inflammation and pulmonary edema
.
Chemical formula
A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....
. It has a characteristic sweet odor that resembles gasoline and kerosene. It is toxic and is a powerful oxidizing
Oxidizing agent
An oxidizing agent can be defined as a substance that removes electrons from another reactant in a redox chemical reaction...
and fluorinating agent. It is the acid fluoride of perchloric acid
Perchloric acid
Perchloric acid is the inorganic compound with the formula HClO4. Usually encountered as an aqueous solution, this colourless compound is a strong acid comparable in strength to sulfuric and nitric acids. It is a powerful oxidizer, but its aqueous solutions up to appr. 70% are remarkably inert,...
.
In spite of its small enthalpy of formation (ΔHf
Electrophile
In general electrophiles are positively charged species that are attracted to an electron rich centre. In chemistry, an electrophile is a reagent attracted to electrons that participates in a chemical reaction by accepting an electron pair in order to bond to a nucleophile...
. It reacts explosively with reducing agents such as amide
Amide
In chemistry, an amide is an organic compound that contains the functional group consisting of a carbonyl group linked to a nitrogen atom . The term refers both to a class of compounds and a functional group within those compounds. The term amide also refers to deprotonated form of ammonia or an...
s, metals, hydride
Hydride
In chemistry, a hydride is the anion of hydrogen, H−, or, more commonly, a compound in which one or more hydrogen centres have nucleophilic, reducing, or basic properties. In compounds that are regarded as hydrides, hydrogen is bonded to a more electropositive element or group...
s, etc.
Synthesis and chemistry
Perchloryl fluoride is produced primarily by the fluorination of perchloratePerchlorate
Perchlorates are the salts derived from perchloric acid . They occur both naturally and through manufacturing. They have been used as a medicine for more than 50 years to treat thyroid gland disorders. They are used extensively within the pyrotechnics industry, and ammonium perchlorate is also a...
s. Antimony pentafluoride
Antimony pentafluoride
Antimony pentafluoride is the inorganic compound with the formula SbF5. This colourless, viscous liquid is a valuable Lewis acid and a component of the superacid fluoroantimonic acid, the strongest known acid...
is a commonly-used fluorinating agent:
- + 3 HF + 2 → + + 2
reacts with alcohol
Alcohol
In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....
s to produce alkyl perchlorates, which are extremely shock-sensitive explosives. Using Friedel-Crafts catalysts, it can be used for introducing the group into aromatic rings via electrophilic aromatic substitution
Electrophilic aromatic substitution
Electrophilic aromatic substitution EAS is an organic reaction in which an atom, usually hydrogen, appended to an aromatic system is replaced by an electrophile...
.
Applications
Perchloryl fluoride is used in organic chemistry as a mild fluorinating agent. It was the first industrially-relevant electrophilicElectrophile
In general electrophiles are positively charged species that are attracted to an electron rich centre. In chemistry, an electrophile is a reagent attracted to electrons that participates in a chemical reaction by accepting an electron pair in order to bond to a nucleophile...
fluorinating agent, used since the 1960s for producing fluorinated steroid
Steroid
A steroid is a type of organic compound that contains a characteristic arrangement of four cycloalkane rings that are joined to each other. Examples of steroids include the dietary fat cholesterol, the sex hormones estradiol and testosterone, and the anti-inflammatory drug dexamethasone.The core...
s.
Perchloryl fluoride was investigated as a high performance liquid rocket fuel oxidizer. In comparison with chlorine pentafluoride
Chlorine pentafluoride
Chlorine pentafluoride is an interhalogen compound with formula ClF5. It was first synthesized in 1963.Its square pyramidal structure with C4v symmetry was confirmed by its high resolution19F NMR spectrum.-Preparation:...
and bromine pentafluoride
Bromine pentafluoride
Bromine pentafluoride, BrF5, is an interhalogen compound and a fluoride of bromine. It is a strong fluorination reagent.It melts at −61.30 °C and boils at 40.25 °C. BrF5 finds use in oxygen isotope analysis. Laser ablation of solid silicates in the presence of bromine pentafluoride releases O2 for...
, it has significantly lower specific impulse
Specific impulse
Specific impulse is a way to describe the efficiency of rocket and jet engines. It represents the derivative of the impulse with respect to amount of propellant used, i.e., the thrust divided by the amount of propellant used per unit time. If the "amount" of propellant is given in terms of mass ,...
, but does not tend to corrode tanks. It does not require cryogenic storage.
It can also be used in flame photometry
Photoelectric flame photometer
A photoelectric flame photometer is a device used in inorganic chemical analysis to determine the concentration of certain metal ions, among them sodium, potassium, lithium, and calcium....
as an excitation source.
Safety
Perchloryl fluoride is toxic, with a TLVThreshold Limit Value
The threshold limit value of a chemical substance is a level to which it is believed a worker can be exposed day after day for a working lifetime without adverse health effects. Strictly speaking, TLV is a reserved term of the American Conference of Governmental Industrial Hygienists...
of 3 ppm. It is a strong lung- and eye-irritant capable of producing burns on exposed skin. Its IDLH
IDLH
IDLH is an initialism for Immediately Dangerous to Life or Health, and is defined by the US National Institute for Occupational Safety and Health as exposure to airborne contaminants that is "likely to cause death or immediate or delayed permanent adverse health effects or prevent escape from such...
level is 385 ppm. Symptoms of exposure include dizziness, headaches, syncope
Syncope (medicine)
Syncope , the medical term for fainting, is precisely defined as a transient loss of consciousness and postural tone characterized by rapid onset, short duration, and spontaneous recovery due to global cerebral hypoperfusion that most often results from hypotension.Many forms of syncope are...
, and cyanosis
Cyanosis
Cyanosis is the appearance of a blue or purple coloration of the skin or mucous membranes due to the tissues near the skin surface being low on oxygen. The onset of cyanosis is 2.5 g/dL of deoxyhemoglobin. The bluish color is more readily apparent in those with high hemoglobin counts than it is...
. Exposure to toxic levels causes severe respiratory tract inflammation and pulmonary edema
Pulmonary edema
Pulmonary edema , or oedema , is fluid accumulation in the air spaces and parenchyma of the lungs. It leads to impaired gas exchange and may cause respiratory failure...
.