Potassium cyanate
Template:Chembox Potassium cyanate is an inorganic compound with the formula KOCN (sometimes denoted KCNO[1]). It is a colourless solid. It is used to prepare many other compounds including useful herbicide. Worldwide production of the potassium and sodium salts was 20,000 tons in 2006.[2]
Structure and bonding
The cyanate anion is isoelectronic with carbon dioxide and with the azide anion, being linear. The C-N distance is 121 pm, about 5 pm longer than for cyanide.[3][4] Potassium cyanate is isostructural with potassium azide.[5]
Uses
The potassium and sodium salts can be used interchangeably for the majority of applications. Potassium cyanate is often preferred to the sodium salt, which is less soluble in water and less readily available in pure form.
Potassium cyanate is used as a basic raw material for various organic syntheses, including, urea derivatives, semicarbazides, carbamates and isocyanates. For example, it is used to prepare the drug hydroxyurea. It is also used for the heat treatment of metals (e.g., Ferritic nitrocarburizing).[2][7]
Therapeutic uses
Potassium cyanate was investigated as a treatment for sickle cell anemia, because it carbamylates the lysine and terminal amines in the deformed hemoglobin, modifying those areas' hydrophobicity.[8] It has similarly been proposed to treat veterinary malaria.[9]
Preparation and reactions
Commercial KOCN is prepared by heating urea with potassium carbonate at 400 °C:
- 2 OC(NH2)2 + K2CO3 → 2 KOCN + (NH4)2CO3
The reaction produces a liquid. Intermediates and impurities include biuret, cyanuric acid, and potassium allophanate (KO2CNHC(O)NH2), as well as unreacted starting urea, but these species are unstable at 400 °C.[2]
Potassium cyanate is also formed by the oxidation of potassium cyanide, either with oxidizing agents or at high temperature in air.[10]
Protonation gives a 97:3 mixture (at room temperature) of two tautomers, HNCO (isocyanic acid) and NCOH (cyanic acid). This mixture is stable at high dilution but trimerizes on concentration to give cyanuric acid.
References
External links
Template:Potassium compounds Template:Cyanates
- ↑ Recreation of Wöhler's Synthesis of Urea: An Undergraduate Organic Laboratory Exercise James D. Batchelor, Everett E. Carpenter, Grant N. Holder, Cassandra T. Eagle, Jon Fielder, Jared Cummings The Chemical Educator 1/Vol .3,NO.6 1998 ISSN 1430-4171 Online article Template:Webarchive
- ↑ 2.0 2.1 2.2 Peter M. Schalke1, "Cyanates, Inorganic Salts" Ullmann's Encyclopedia of Industrial Chemistry2006, Wiley-VCH, Weinheim. Template:Doi. Article Online Posting Date: July 15, 2006
- ↑ Template:Greenwood&Earnshaw2nd
- ↑ Jursík, F. (2001). Anorganická chemie nekovů (1. vydání). VŠCHT Praha. Template:ISBN
- ↑ T. C. Waddington "Lattice parameters and infrared spectra of some inorganic cyanates" J. Chem. Soc., 1959, 2499-2502. Template:Doi
- ↑ Ulrich Müller "Verfeinerung der Kristallstrukturen von KN3, RbN3, CsN3 und TIN3" Zeitschrift für anorganische und allgemeine Chemie 1972, Volume 392, 159–166. Template:Doi
- ↑ INEOS Paraform GmbH, Potassium Cyanate (KOCN) product information. Online version accessed on 2009-06-30.
- ↑ Template:Cite journal See also Template:Cite patent
- ↑ Template:Cite patent
- ↑ Template:Kirk-Othmer