Nitrosyl chloride

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Nitrosyl chloride
Nitrosyl chloride
Nitrosyl chloride
IUPAC name Nitrosyl chloride
Other names Nitrogen oxychloride
Nitrosonium chloride
Identifiers
CAS number [2696-92-6]
SMILES O=N(Cl)
Properties
Molecular formula ClNO
Molar mass 65.46 g/mol
Appearance yellow gas, red liquid
Density 1.417 g/cm3, liquid @ -12 °C
2.99 g/L, gas
Melting point

-59.6 °C
Boiling point

-6.4 °C
Solubility in water decomposes
Solubility in other solvents chlorocarbons
Structure
Molecular shape sp2 at N
Dipole moment 1.90 D
Hazards
Main hazards highly toxic
Related compounds
Related compounds NO
NOHSO4
NOBF4
SNCl
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)
Infobox disclaimer and references

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.

Contents

[edit] Structure and synthesis

Although its formula is written NOCl, the structure is better represented ONCl. A double bond 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°.[1]

NOCl can be prepared by the direct combination of chlorine and nitric oxide. Alternatively, nitrosylsulfuric acid and HCl also affords the compound:

HCl + NOHSO4 → NOCl + H2SO4

It also arises from the combination of hydrochloric and nitric acids according to the following reaction:[2]

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 in 1831.[3]

[edit] Reactions

  • NOCl reacts with halide acceptors to give the nitrosyl cation, [NO]+. This species is available as NOBF4.
  • NOCl reacts with water to release HCl.
  • Heating NOCl above 100 C gives back Cl2 and NO.
  • In organic synthesis, NOCl is often employed. It adds to alkenes to afford α-chloro oximes.[4]

[edit] Safety

NOCl is toxic and irritating to the lungs.

[edit] References

  1. ^ Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.
  2. ^ L. J. Beckham, W. A. Fessler, M. A. Kise (1951). "Nitrosyl Chloride". Chemical Reviews 48: 319–396. doi:10.1021/cr60151a001. 
  3. ^ Edmund Davy (1830 - 1837). "Abstracts of the Papers Printed in the Philosophical Transactions of the Royal Society of London, Vol. 3.": 27–29. 
  4. ^ Ohno, M,; Naruse, N.; Terasawa, I. (1973). "7-cyanoheptanal". Org. Synth.; Coll. Vol. 5: 266.