Nitrosyl chloride
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| Nitrosyl chloride | |
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| General | |
| Systematic name | Nitrosyl chloride |
| Other names | Nitrogen oxychloride Nitrosonium chloride |
| Molecular formula | ClNO |
| Molar mass | 65.46 g/mol |
| Appearance | yellow gas, red liquid |
| CAS number | [2696-92-6] |
| SMILES | O=N(Cl) |
| Properties | |
| Density and phase | liq: 1.417 g/cm3 (-12 °C) gas: 2.99 g/L |
| Solubility in water | decomposes |
| Other solvents | chlorocarbons |
| Melting point | -59.6 °C (? K) |
| Boiling point | -6.4 °C (? K) |
| Structure | |
| Molecular shape | sp2 at N |
| Dipole moment | 1.90 D |
| Hazards | |
| MSDS | External MSDS |
| Main hazards | highly toxic |
| NFPA 704 | |
| R/S statement | R: ? S: ? |
| RTECS number | ? |
| Supplementary data page | |
| Structure and properties |
n, εr, etc. |
| Thermodynamic data |
Phase behaviour Solid, liquid, gas |
| Spectral data | IR 1800 (νNO), 596, 332 cm-1 |
| 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 |
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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. It is the mixed acid anhydride of HCl and nitrous 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 fist discription 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
- ^ Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.
- ^ L. J. Beckham, W. A. Fessler, M. A. Kise (1951). "Nitrosyl Chloride". Chemical Reviews 48: 319-396. DOI:10.1021/cr60151a001.
- ^ Edmund Davy (1830 - 1837). "Abstracts of the Papers Printed in the Philosophical Transactions of the Royal Society of London, Vol. 3.": 27-29.
- ^ Ohno, M,; Naruse, N.; Terasawa, I. " 7-cyanoheptanal" Organic Syntheses, Collected Volume 5, page.266 (1973). (addition of NOCl to cyclooctene)
