Nitrosyl chloride
Encyclopedia
Nitrosyl chloride is the chemical compound
NOCl. It is a yellow gas that is most commonly encountered as a decomposition product of aqua regia
, a mixture of hydrochloric acid
and nitric acid
. The related nitrosyl halides nitrosyl fluoride
, NOF, and nitrosyl bromide, NOBr, are also known.
exists between N and O (distance = 1.16 Å) and a single bond between N and Cl (distance = 1.69 Å). The O-N-Cl angle is 113°.
NOCl can be prepared by the direct combination of chlorine
and nitric oxide
. Alternatively, nitrosylsulfuric acid
and HCl also affords the compound:
It also arises from the combination of hydrochloric and nitric acids according to the following reaction:
Although this mixture was used for dissolving gold for a long time the first description of the gas was done by Edmund Davy
in 1831.
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...
NOCl. It is a yellow gas that is most commonly encountered as a decomposition product of aqua regia
Aqua regia
Aqua regia or aqua regis is a highly corrosive mixture of acids, fuming yellow or red solution, also called nitro-hydrochloric acid. The mixture is formed by freshly mixing concentrated nitric acid and hydrochloric acid, usually in a volume ratio of 1:3, respectively...
, a mixture of hydrochloric acid
Hydrochloric acid
Hydrochloric acid is a solution of hydrogen chloride in water, that is a highly corrosive, strong mineral acid with many industrial uses. It is found naturally in gastric acid....
and nitric acid
Nitric acid
Nitric acid , also known as aqua fortis and spirit of nitre, is a highly corrosive and toxic strong acid.Colorless when pure, older samples tend to acquire a yellow cast due to the accumulation of oxides of nitrogen. If the solution contains more than 86% nitric acid, it is referred to as fuming...
. The related nitrosyl halides nitrosyl fluoride
Nitrosyl fluoride
Nitrosyl fluoride, NOF, is a covalently bonded nitrosyl compound.-Reactions:NOF is a highly reactive fluorinating agent that converts many metals to their fluorides, releasing nitric oxide:...
, NOF, and nitrosyl bromide, NOBr, are also known.
Structure and synthesis
A double bondDouble bond
A double bond in chemistry is a chemical bond between two chemical elements involving four bonding electrons instead of the usual two. The most common double bond, that between two carbon atoms, can be found in alkenes. Many types of double bonds between two different elements exist, for example in...
exists between N and O (distance = 1.16 Å) and a single bond between N and Cl (distance = 1.69 Å). The O-N-Cl angle is 113°.
NOCl can be prepared by the direct combination of chlorine
Chlorine
Chlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...
and nitric oxide
Nitric oxide
Nitric oxide, also known as nitrogen monoxide, is a diatomic molecule with chemical formula NO. It is a free radical and is an important intermediate in the chemical industry...
. Alternatively, nitrosylsulfuric acid
Nitrosylsulfuric acid
Nitrosylsulfuric acid is the chemical compound with the formula NOHSO4.This salt is a source of the NO+ ion, It can also be viewed as the mixed acid anhydride of sulfuric acid and nitrous acid:...
and HCl also affords the compound:
- HCl + NOHSO4 → NOCl + H2SO4Sulfuric acidSulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...
It also arises from the combination of hydrochloric and nitric acids according to the following reaction:
- HNO3 + 3 HCl → Cl2 + 2 H2O + NOCl
Although this mixture was used for dissolving gold for a long time the first description of the gas was done by Edmund Davy
Edmund Davy
Edmund Davy FRS was a professor of Chemistry at the Royal Cork Institution from 1813 and professor of chemistry at the Royal Dublin Society from 1826. He discovered acetylene, as it was later named by Marcellin Berthelot...
in 1831.
Reactions
- NOCl reacts with halideHalideA halide is a binary compound, of which one part is a halogen atom and the other part is an element or radical that is less electronegative than the halogen, to make a fluoride, chloride, bromide, iodide, or astatide compound. Many salts are halides...
acceptors to give the nitrosyl cation, [NO]+. This species is available as NOBF4Nitrosonium tetrafluoroborateNitrosonium tetrafluoroborate, also called nitrosyl tetrafluoroborate, is a chemical compound with the chemical formula NOBF4. This colourless solid finds use in organic synthesis as a nitrosating agent....
. - NOCl reacts with water to release HCl.
- Heating NOCl above 100°C gives back Cl2 and NO.
- In organic synthesisOrganic synthesisOrganic synthesis is a special branch of chemical synthesis and is concerned with the construction of organic compounds via organic reactions. Organic molecules can often contain a higher level of complexity compared to purely inorganic compounds, so the synthesis of organic compounds has...
, NOCl is often employed. It adds to alkeneAlkeneIn organic chemistry, an alkene, olefin, or olefine is an unsaturated chemical compound containing at least one carbon-to-carbon double bond...
s to afford α-chloro oximeOximeAn oxime is a chemical compound belonging to the imines, with the general formula R1R2C=NOH, where R1 is an organic side chain and R2 may be hydrogen, forming an aldoxime, or another organic group, forming a ketoxime. O-substituted oximes form a closely related family of compounds...
s. - NOCl photolysesPhotodissociationPhotodissociation, photolysis, or photodecomposition is a chemical reaction in which a chemical compound is broken down by photons. It is defined as the interaction of one or more photons with one target molecule....
to NO and a Cl radical.