Nitrosylsulfuric acid

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Nitrosylsulfuric acid
Nitrosylsulfuric acid structure.svg
Nitrosylsulfuric acid molecule ball.png
Names
IUPAC name
Nitrosylsulfuric acid
Other names
nitrosonium bisulfate, chamber crystals
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.029.058 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
UNII
  • InChI=1S/HNO5S/c2-1-6-7(3,4)5/h(H,3,4,5) Yes check.svgY
    Key: VQTGUFBGYOIUFS-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/HNO5S/c2-1-6-7(3,4)5/h(H,3,4,5)
    Key: VQTGUFBGYOIUFS-UHFFFAOYAM
  • O=NOS(=O)(=O)O
Properties
HSO4NO
Molar mass 127.08 g/mol
AppearancePale yellow crystals [1]
Density 1.865 g/mL in
40% sulfuric acid soln [2]
Melting point 70 °C (158 °F; 343 K) [1]
Boiling point Decomposes
Decomposes
Solubility Soluble in H2SO4 [1]
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Oxidizer
Related compounds
Other anions
NOCl
Other cations
NaHSO4
Related compounds
NOBF4
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Nitrosylsulfuric acid is the chemical compound with the formula HSO4NO. It is a colourless solid that is used industrially in the production of caprolactam, [3] and was formerly part of the lead chamber process for producing sulfuric acid. The compound is the mixed anhydride of sulfuric acid and nitrous acid.

Contents

In organic chemistry, it is used as a reagent for nitrosating, as a diazotizing agent, and as an oxidizing agent. [1]

Synthesis and reactions

A typical procedure entails dissolving sodium nitrite in cold sulfuric acid: [4] [5]

HNO2 + H2SO4 → HSO4NO + H2O

It can also be prepared by the reaction of nitric acid and sulfur dioxide. [6]

HSO4NO is used in organic chemistry to prepare diazonium salts from amines, for example in the Sandmeyer reaction. Related NO-delivery reagents include nitrosonium tetrafluoroborate [NO]+[BF4] and nitrosyl chloride.

In industry, the nitrosodecarboxylation reaction between nitrosylsulfuric acid and cyclohexanecarboxylic acid is used to generate caprolactam: [3] This is known as the Snia Viscosa process

Nitrosodecarboxylation Caprolactam Synthesis.svg

Safety

Nitrosylsulfuric acid is a hazardous material and precautions are indicated. [1]

References

  1. 1 2 3 4 5 George A. Olah, G. K. Surya Prakash, Qi Wang, Xing-Ya Li (2001). "Nitrosylsulfuric Acid". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rn060. ISBN   978-0471936237.{{cite book}}: |journal= ignored (help)CS1 maint: multiple names: authors list (link)
  2. "Nitrosylsulfuric acid solution". Merck.
  3. 1 2 Ritz, J.; Fuchs, H.; Kieczka, H.; Moran, W. C. (2002). "Caprolactam". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a05_031. ISBN   978-3527306732.
  4. Hodgson, H. H.; Mahadevan, A. P.; Ward, E. R. (1955). "1,4-Dinitronaphthalene". Organic Syntheses ; Collected Volumes, vol. 3, p. 341. (diazodization followed by treatment with nitrite)
  5. Sandin, R. B.; Cairns, T. L. (1943). "1,2,3-Triiodo-5-nitrobenzene". Organic Syntheses ; Collected Volumes, vol. 2, p. 604. (diazodization followed by treatment with iodide)
  6. Coleman, G. H.; Lillis, G. A.; Goheen, G. E. (1939). "Nitrosyl Chloride". Inorganic Syntheses. Vol. 1. pp. 55–59. doi:10.1002/9780470132326.ch20. ISBN   9780470132326.{{cite book}}: ISBN / Date incompatibility (help) This procedure generates the nitrosylsulfuric acid as an intermediate en route to NOCl.