Tetrafluorohydrazine or perfluorohydrazine, , is a colourless, nonflammable,
reactive
inorganic
An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bondsthat is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemistry''.
Inor ...
gas
Gas is a state of matter that has neither a fixed volume nor a fixed shape and is a compressible fluid. A ''pure gas'' is made up of individual atoms (e.g. a noble gas like neon) or molecules of either a single type of atom ( elements such as ...
. It is a
fluorinated
In chemistry, halogenation is a chemical reaction which introduces one or more halogens into a chemical compound. Halide-containing compounds are pervasive, making this type of transformation important, e.g. in the production of polymers, drugs. ...
analog of
hydrazine
Hydrazine is an inorganic compound with the chemical formula . It is a simple pnictogen hydride, and is a colourless flammable liquid with an ammonia-like odour. Hydrazine is highly hazardous unless handled in solution as, for example, hydraz ...
.
Synthesis
Tetrafluorohydrazine was originally prepared from
nitrogen trifluoride
Nitrogen trifluoride is the inorganic compound with the formula (). It is a colorless, non-flammable, toxic gas with a slightly musty odor. In contrast with ammonia, it is nonbasic. It finds increasing use within the manufacturing of flat-panel ...
using a
copper
Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...
as a fluorine atom acceptor:
:
A number of F-atom acceptors can be used, including carbon, other metals, and
nitric oxide
Nitric oxide (nitrogen oxide, nitrogen monooxide, or nitrogen monoxide) is a colorless gas with the formula . It is one of the principal oxides of nitrogen. Nitric oxide is a free radical: it has an unpaired electron, which is sometimes den ...
. These reactions exploit the relatively weak N-F bond in NF
3.
Properties
Tetrafluorohydrazine is in equilibrium with its radical monomer
nitrogen difluoride
Nitrogen difluoride, also known as difluoroamino, is a reactive radical molecule with formula . This small molecule is in equilibrium with its dimer tetrafluorohydrazine.
:
As the temperature increases the proportion of increases.
The molecule ...
.
:
At room temperature is mostly associated with only 0.7% in the form of at 5mm Hg pressure. When the temperature rises to 225 °C, it mostly dissociates with 99% in the form of .
[ molecule dimensions and angles]
The energy needed to break the N−N bond in is 20.8 kcal/mol, with an entropy change of 38.6
eu.
For comparison, the dissociation energy of the N−N bond is in
, in
, and in
. The
enthalpy of formation
In chemistry and thermodynamics, the standard enthalpy of formation or standard heat of formation of a compound is the change of enthalpy during the formation of 1 mole of the substance from its constituent elements in their reference state, wi ...
of (Δ
f''H''°) is 34.421 kJ/mol.
Uses
Tetrafluorohydrazine is used in
organic synthesis
Organic synthesis is a branch of chemical synthesis concerned with the construction of organic compounds. Organic compounds are molecules consisting of combinations of covalently-linked hydrogen, carbon, oxygen, and nitrogen atoms. Within the gen ...
and some experimental
rocket propellant
Rocket propellant is used as reaction mass ejected from a rocket engine to produce thrust. The energy required can either come from the propellants themselves, as with a chemical rocket, or from an external source, as with ion engines.
Overvi ...
formulations.
It
adds
Applied Digital Data Systems, Inc. (ADDS), was a supplier of video display computer terminals, founded in 1969 by Leeam Lowin and William J. Catacosinos. Lowin simultaneously founded Solid State Data Sciences (SSDS). SSDS was one of the first d ...
across
double bond
In chemistry, a double bond is a covalent bond between two atoms involving four bonding electrons as opposed to two in a single bond. Double bonds occur most commonly between two carbon atoms, for example in alkenes. Many double bonds exist betw ...
s to give
vicinal di(difluoroamine)s. In
chemical syntheses, as a precursor or a
catalyst
Catalysis () is the increase in rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quick ...
. It was considered for use as a high-energy liquid
oxidizer
An oxidizing agent (also known as an oxidant, oxidizer, electron recipient, or electron acceptor) is a substance in a redox chemical reaction that gains or " accepts"/"receives" an electron from a (called the , , or ''electron donor''). In ot ...
in some never-flown
rocket propellant
Rocket propellant is used as reaction mass ejected from a rocket engine to produce thrust. The energy required can either come from the propellants themselves, as with a chemical rocket, or from an external source, as with ion engines.
Overvi ...
formulas in 1959.
Tetrafluorohydrazine
at DTIC.mil archived March 12, 2007
Safety
Tetrafluorohydrazine is a highly hazardous chemical that explodes in the presence of organic
Organic may refer to:
* Organic, of or relating to an organism, a living entity
* Organic, of or relating to an anatomical organ
Chemistry
* Organic matter, matter that has come from a once-living organism, is capable of decay or is the product ...
materials.
It is a toxic chemical which irritates skin, eyes and lungs. It is a neurotoxin
Neurotoxins are toxins that are destructive to nervous tissue, nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological insult (medical), insultsSpencer 2000 that can adversely affect function ...
and may cause methemoglobinemia
Methemoglobinemia, or methaemoglobinaemia, is a condition of elevated methemoglobin in the blood. Symptoms may include headache, dizziness, shortness of breath, nausea, poor muscle coordination, and blue-colored skin (cyanosis). Complications ma ...
. It may be fatal if inhaled or absorbed through skin. Vapors may be irritating and corrosive. It is a strong oxidizing agent
An oxidizing agent (also known as an oxidant, oxidizer, electron recipient, or electron acceptor) is a substance in a redox chemical reaction that gains or " accepts"/"receives" an electron from a (called the , , or ''electron donor''). In ot ...
. Contact with this chemical may cause burns and severe injury. Fire produces irritating, corrosive and toxic gases. Vapors from liquefied gas
Liquefied gas (sometimes referred to as liquid gas) is a gas that has been turned into a liquid by cooling or compressing it. Examples of liquefied gases include liquid air, liquefied natural gas, and liquefied petroleum gas.
Liquid air
At the ...
are initially heavier than air
An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosph ...
and spread across the ground.
Tetrafluorohydrazine explodes or ignites on contact with reducing agents
In chemistry, a reducing agent (also known as a reductant, reducer, or electron donor) is a chemical species that "donates" an electron to an (called the , , , or ).
Examples of substances that are common reducing agents include hydrogen, carbon ...
at room temperature
Room temperature, colloquially, denotes the range of air temperatures most people find comfortable indoors while dressed in typical clothing. Comfortable temperatures can be extended beyond this range depending on humidity, air circulation, and ...
, including hydrogen
Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...
, hydrocarbons
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic; their odor is usually faint, and may b ...
, alcohols
In chemistry, an alcohol (), is a type of organic compound that carries at least one hydroxyl () functional group bound to a Saturated and unsaturated compounds, saturated carbon atom. Alcohols range from the simple, like methanol and ethanol ...
, thiols
In organic chemistry, a thiol (; ), or thiol derivative, is any organosulfur compound of the form , where R represents an alkyl or other organic substituent. The functional group itself is referred to as either a thiol group or a sulfhydryl grou ...
, amines
In chemistry, amines (, ) are organic compounds that contain carbon-nitrogen bonds. Amines are formed when one or more hydrogen atoms in ammonia are replaced by alkyl or aryl groups. The nitrogen atom in an amine possesses a lone pair of elec ...
, ammonia
Ammonia is an inorganic chemical compound of nitrogen and hydrogen with the chemical formula, formula . A Binary compounds of hydrogen, stable binary hydride and the simplest pnictogen hydride, ammonia is a colourless gas with a distinctive pu ...
, hydrazines
Hydrazines (R2N−NR2) are a class of chemical compounds with two nitrogen atoms linked via a covalent bond and which carry from one up to four alkyl or aryl substituents. Hydrazines can be considered as derivatives of the inorganic hydrazine ( ...
, dicyanogen, nitroalkanes, alkylberylliums, silanes
In organosilicon chemistry, silanes are a diverse class of charge-neutral organic compounds with the general formula . The R substituents can be any combination of organic or inorganic groups. Most silanes contain Si-C bonds, and are discussed ...
, boranes
A borane is a compound with the formula although examples include multi-boron derivatives. A large family of boron hydride clusters is also known. In addition to some applications in organic chemistry, the boranes have attracted much attention ...
or powdered metals
A metal () is a material that, when polished or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. These properties are all associated with having electrons available at the Fermi level, as against no ...
. Prolonged exposure of the container of tetrafluorohydrazine to high heat may cause it to rupture violently and rocket. Tetrafluorohydrazine itself can explode at high temperatures or with shock or blast when under pressure. When heated to decomposition in air, it emits highly toxic fumes of fluorine
Fluorine is a chemical element; it has Chemical symbol, symbol F and atomic number 9. It is the lightest halogen and exists at Standard temperature and pressure, standard conditions as pale yellow Diatomic molecule, diatomic gas. Fluorine is extre ...
and oxides of nitrogen
Nitrogen oxide may refer to a binary compound of oxygen and nitrogen, or a mixture of such compounds:
Charge-neutral
*Nitric oxide (NO), nitrogen(II) oxide, or nitrogen monoxide
*Nitrogen dioxide (), nitrogen(IV) oxide
* Nitrogen trioxide (), or ...
.
There is a fatal case in which during opening of valves to check the pressure, the cylinder exploded, killing one man and injuring another.
References
{{Hydrazines
Nitrogen fluorides
Rocket oxidizers
Hydrazines
Gases
Neurotoxins