Dinitrogen difluoride
Encyclopedia
Dinitrogen difluoride is a chemical compound
with the formula N2F2. It is a gas at room temperature, and was first identified in 1952 as the thermal decomposition
product of the azide
N3F. It has the structure F-N=N-F and exists in both a cis- and trans-form. These isomers are thermally interconvertible but can be separated by low temperature fractionation
. The trans-form is less thermodynamically stable but can be stored in glass vessels. The cis-form attacks glass over a time scale of about 2 weeks to form silicon tetrafluoride
and nitrous oxide
:
Most preparations of dinitrogen difluoride give mixtures of the two isomers, but they can be prepared independently.
The cis form of dinitrogen difluoride will react with strong fluoride ion accepters such as antimony pentafluoride
to form N2F+ cation.
In the solid phase of N2F+ compound, the observed N−N and N−F bond distances of 1.089(9) and 1.257(8) Å, respectively, are among the shortest experimentally observed N−N and N−F bonds
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
with the formula N2F2. It is a gas at room temperature, and was first identified in 1952 as the thermal decomposition
Thermal decomposition
Thermal decomposition, or thermolysis, is a chemical decomposition caused by heat. The decomposition temperature of a substance is the temperature at which the substance chemically decomposes....
product of the azide
Azide
Azide is the anion with the formula N3−. It is the conjugate base of hydrazoic acid. N3− is a linear anion that is isoelectronic with CO2 and N2O. Per valence bond theory, azide can be described by several resonance structures, an important one being N−=N+=N−...
N3F. It has the structure F-N=N-F and exists in both a cis- and trans-form. These isomers are thermally interconvertible but can be separated by low temperature fractionation
Fractionation
See also: Fractionated spacecraftFractionation is a separation process in which a certain quantity of a mixture is divided up in a number of smaller quantities in which the composition changes according to a gradient. Fractions are collected based on differences in a specific property of the...
. The trans-form is less thermodynamically stable but can be stored in glass vessels. The cis-form attacks glass over a time scale of about 2 weeks to form silicon tetrafluoride
Silicon tetrafluoride
Silicon tetrafluoride or Tetrafluorosilane is the chemical compound with the formula SiF4. This tetrahedral molecule is notable for having a remarkably narrow liquid range...
and nitrous oxide
Nitrous oxide
Nitrous oxide, commonly known as laughing gas or sweet air, is a chemical compound with the formula . It is an oxide of nitrogen. At room temperature, it is a colorless non-flammable gas, with a slightly sweet odor and taste. It is used in surgery and dentistry for its anesthetic and analgesic...
:
- 2 N2F2 + SiO2 → SiF4 + 2 N2O
Most preparations of dinitrogen difluoride give mixtures of the two isomers, but they can be prepared independently.
The cis form of dinitrogen difluoride will react with strong fluoride ion accepters such as 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...
to form N2F+ cation.
- N2F2 + SbF5 → N2F+[SbF6]-
In the solid phase of N2F+ compound, the observed N−N and N−F bond distances of 1.089(9) and 1.257(8) Å, respectively, are among the shortest experimentally observed N−N and N−F bonds