Potassium cyanate is an inorganic compound with the formula KOCN (sometimes denoted KCNORecreation 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 ). 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.Peter M. Schalke1, "Cyanates, Inorganic Salts" Ullmann's Encyclopedia of Industrial Chemistry2006, Wiley-VCH, Weinheim. . Article Online Posting Date: July 15, 2006
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.Jursík, F. (2001). Anorganická chemie nekovů (1. vydání). VŠCHT Praha. Potassium cyanate is isostructural with potassium azide.T. C. Waddington "Lattice parameters and infrared spectra of some inorganic cyanates" J. Chem. Soc., 1959, 2499-2502.
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).INEOS Paraform GmbH, Potassium Cyanate (KOCN) product information. Online version accessed on 2009-06-30.
Therapeutic uses Potassium cyanate was investigated as a treatment for sickle cell anemia, because it carbamylates the lysines and terminal amine in deformed hemoglobin, modifying those areas' hydrophobicity. See also It has similarly been proposed to treat veterinary malaria.
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.
Potassium cyanate is also formed by the oxidation of potassium cyanide, either with oxidizing agents or at high temperature in air.
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 MSDS MSDS at jtbaker.com