Sodium cyanate
Identifiers
3D model (JSmol)
3655041
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.011.846 Edit this at Wikidata
EC Number
  • 213-030-6
MeSH C009281
UNII
  • InChI=1S/CHNO.Na/c2-1-3;/h3H;/q;+1/p-1
    Key: ZVCDLGYNFYZZOK-UHFFFAOYSA-M
  • C(#N)[O-].[Na+]
Properties
NaOCN
Molar mass 65.01 g/mol
Appearance white crystalline solid
Odor odorless
Density 1.893 g/cm3
Melting point 550 °C (1,022 °F; 823 K)
11.6 g/100 mL (25 °C)
Solubility ethanol: 0.22 g/100 mL (0 °C)
dimethylformamide: 0.05 g/100 mL (25 °C)
slightly soluble in ammonia, benzene
insoluble in diethyl ether
Structure
body centered rhombohedral
Thermochemistry
86.6 J/mol K
119.2 J/mol K
−400 kJ/mol
Hazards
GHS labelling:
GHS07: Exclamation mark
Warning
H302, H412
P264, P270, P273, P301+P312, P330, P501
Lethal dose or concentration (LD, LC):
1500 mg/kg (rat, oral)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Sodium cyanate is the inorganic compound with the formula NaOCN. A white solid, it is the sodium salt of the cyanate anion.

Structure

The anion is described by two resonance structures: N≡C−O− and −N=C=O

The salt adopts a body centered rhombohedral crystal lattice structure (trigonal crystal system) at room temperature.[1]

Preparation

Sodium cyanate is prepared industrially by the reaction of urea with sodium carbonate at elevated temperature.

2OC(NH2)2 + Na2CO3 → 2Na(NCO) + CO2 + 2NH3 + H2O

Sodium allophanate is observed as an intermediate:[2]

H2NC(O)NHCO2Na → NaOCN + NH3 + CO2

It can also be prepared in the laboratory by oxidation of a cyanide in aqueous solution by a mild oxidizing agent such as lead oxide.[3]

Uses and reactions

The main use of sodium cyanate is for steel hardening.[2]

Sodium cyanate is used to produce cyanic acid, often in situ:

NaOCN + HCl → HOCN + NaCl

This approach is exploited for condensation with amines to give unsymmetrical ureas:

HOCN + RNH2 → RNHC(O)NH2

Such urea derivatives have a range of biological activity.[4]

See also

References

  1. ^ Waddington, T.C. "Journal of the Chemical Society (Resumed)." 499. Lattice Parameters and Infrared Spectra of Some Inorganic Cyanates - (RSC Publishing). N.p., n.d. Web. 09 Nov. 2014.
  2. ^ a b Schalke, Peter M. (2006). "Cyanates, Inorganic Salts". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a08_157.pub2. ISBN 3527306730.
  3. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 324. ISBN 978-0-08-037941-8.
  4. ^ Vinogradova, Ekaterina V.; Fors, Brett P.; Buchwald, Stephen L. (11 July 2012). "Palladium-Catalyzed Cross-Coupling of Aryl Chlorides and Triflates with Sodium Cyanate: A Practical Synthesis of Unsymmetrical Ureas". Journal of the American Chemical Society. 134 (27): 11132–11135. doi:10.1021/ja305212v. PMC 3472423. PMID 22716197.


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