Adverts

Open Access Articles- Top Results for Isocyanic acid

Isocyanic acid

Isocyanic acid
200px
200px
colspan=2 style="background:#f8eaba; border-top:2px solid transparent; border-bottom:2px solid transparent; text-align:center;" #REDIRECTmw:Help:Magic words#Other
This page is a soft redirect. Names

#REDIRECTmw:Help:Magic words#Other
This page is a soft redirect.-

IUPAC name
Isocyanic acid
colspan=2 style="background:#f8eaba; border-top:2px solid transparent; border-bottom:2px solid transparent; text-align:center;" #REDIRECTmw:Help:Magic words#Other
This page is a soft redirect. Identifiers#REDIRECTmw:Help:Magic words#Other
This page is a soft redirect.-



75-13-8 7pxY
420-05-3 (cyanic acid) 7pxN
ChEBI CHEBI:29202 7pxY
ChemSpider 6107 7pxY
Jmol-3D images Image
PubChem Template:Chembox PubChem/format
colspan=2 style="background:#f8eaba; border-top:2px solid transparent; border-bottom:2px solid transparent; text-align:center;" #REDIRECTmw:Help:Magic words#Other
This page is a soft redirect. Properties

#REDIRECTmw:Help:Magic words#Other
This page is a soft redirect.-

HNCO
Molar mass 43.03 g/mol
Appearance Colorless liquid or gas (b.p. near room temperature)
Density 1.14 g/cm3 (20 °C)
Melting point Script error: No such module "convert".[1]
Boiling point Script error: No such module "convert".
Dissolves
Solubility Soluble in benzene, toluene, ether
colspan=2 style="background:#f8eaba; border-top:2px solid transparent; border-bottom:2px solid transparent; text-align:center;" #REDIRECTmw:Help:Magic words#Other
This page is a soft redirect. Hazards

#REDIRECTmw:Help:Magic words#Other
This page is a soft redirect.-

Main hazards Poisonous
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
 14pxN verify (what is10pxY/10pxN?)
Infobox references

Isocyanic acid is an organic compound with the formula HNCO, discovered in 1830 by Liebig and Wöhler.[2] This colourless substance is volatile and poisonous, with a boiling point of 23.5 °C. Isocyanic acid is the simplest stable chemical compound that contains carbon, hydrogen, nitrogen, and oxygen, the four most commonly found elements in organic chemistry and biology.

Preparation and reactions

Isocyanic acid can be made by protonation of the cyanate anion, such as from salts like potassium cyanate, by either gaseous hydrogen chloride or acids such as oxalic acid.[3]

H+ + NCO- → HNCO

HNCO also can be made by the high-temperature thermal decomposition of cyanuric acid, a trimer.

C3H3N3O3 → 3 HNCO

Isocyanic acid hydrolyses to carbon dioxide and ammonia:

HNCO + H2O → CO2 + NH3

At sufficiently high concentrations, isocyanic acid oligomerizes to give cyanuric acid and cyamelide, a polymer. These species usually are easily separated from liquid- or gas-phase reaction products. Dilute solutions of isocyanic acid are stable in inert solvents, e.g. ether and chlorinated hydrocarbons.[4]

Isocyanic acid reacts with amines to give ureas (carbamides):

HNCO + RNH2 → RNHC(O)NH2.

This reaction is called carbamylation.

HNCO adds across electron-rich double bonds, such as vinylethers, to give the corresponding isocyanates.

Isocyanic acid is also present in various forms of smoke, including smog and cigarette smoke. It was detected using mass spectrometry, and easily dissolves in water, posing a health risk to the lungs.[5]

Isomers: Cyanic acid and fulminic acid

Low-temperature photolysis of solids containing HNCO has been shown to make H-O-C≡N, known as cyanic acid or hydrogen cyanate; it is a tautomer of isocyanic acid.[6] Pure cyanic acid has not been isolated, and isocyanic acid is the predominant form in all solvents.[4] Note that sometimes information presented for cyanic acid in reference books is actually for isocyanic acid.

Cyanic and isocyanic acids are isomers of fulminic acid (H-C=N-O), an unstable compound.[7]

See also

References

  1. ^ Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0-07-049439-8
  2. ^ Liebig, J.; Wöhler, F. (1830). "Untersuchungen über die Cyansäuren". Ann. Phys. 20 (11): 394. Bibcode:1830AnP....96..369L. doi:10.1002/andp.18300961102. 
  3. ^ Fischer, G.; Geith, J.; Klapötke, T. M.; Krumm B. (2002). "Synthesis, Properties and Dimerization Study of Isocyanic Acid" (PDF). Z. Naturforschung 57b (1): 19–25. 
  4. ^ a b A. S. Narula, K. Ramachandran “Isocyanic Acid” in Encyclopedia of Reagents for Organic Synthesis, 2001, John Wiley & Sons, New York. doi:10.1002/047084289X.ri072m Article Online Posting Date: April 15, 2001.
  5. ^ Preidt, Robert. "Chemical in Smoke May Pose Health Risk". MyOptumHealth. AccuWeather. Retrieved 14 September 2011. 
  6. ^ Jacox, M.E.; Milligan, D.E. (1964). "Low-Temperature Infrared Study of Intermediates in the Photolysis of HNCO and DNCO". Journal of Chemical Physics 40 (9): 2457–2460. Bibcode:1964JChPh..40.2457J. doi:10.1063/1.1725546. 
  7. ^ Kurzer, Frederick (2000). "Fulminic Acid in the History of Organic Chemistry". Journal of Chemical Education 77 (7): 851–857. Bibcode:2000JChEd..77..851K. doi:10.1021/ed077p851. 

Further reading

  • Handbook of Chemistry and Physics, 65th. Edition, CRC Press (1984)

External links

Template:Hydrogen compounds

Lua error in Module:Authority_control at line 346: attempt to index field 'wikibase' (a nil value).