Potassium selenocyanate

Selenium reacts with pure potassium cyanide to form potassium selenocyanate, which can also be obtained by reacting in hot water or ethanol:

Se + KCN → KSeCN

However, the reaction of selenocyanate ions with alcohols produces odorous alkyl selenocyanates, and the reaction in ethanol is also undesirable.

Selenium reacts with potassium ferrocyanide to obtain potassium selenocyanate: K4[Fe(CN)6] + 4 Se → eutectic → 4 KSeCN + FeC2 + N2 →

Potassium selenocyanate, a crystalline solid, is a reagent for the conversion of alkyl halides to nitriles and for the production of pharmaceutical intermediates. It is also used in the field of energy storage devices.

white to light beige crystalline powder or needles

Increasing interest in solid state NMR of heavy-metal nuclei results in the preparation of several Hg-thiocyanate and selenocyanate compounds as potential models. Bowmaker, G.A. et al. Inorg. Chem. 1998, 37, 1734.

Potassium selenocyanate is used to prepare triphenylphosphine selenide by reacting with triphenylphosphine. It finds application in solid state NMR of heavy-metal nuclei which results in the preparation of several mercury thiocyanate and selenocyanate compounds.

Potassium selenocyanate can be used to:
(1) Redox-active electrolyte to enhance the performance of carbon-based supercapacitors.
(2) Starting material for the one-pot stereoselective synthesis of alkyl styryl selenides.
(3) Precursor to synthesize Cu and Ni complexes with antioxidant/anti-inflammatory activities.
(4) Selenylating agent to prepare stereoselective selenoglycosides and selenium-linked disaccharides.

Poison by intraperitoneal route. When heated to decomposition it emits very toxic fumes of NOx, CN-, K2O, and Se. See also SELENIUM COMPOUNDS and CYANATES.

Crystalline KSeCN is hygroscopic and decomposes with the elimination of selenium upon prolonged exposure to air. It should be stored in sealed containers. Potassium selenocyanate is a malodorous and highly toxic compound. All reactions and handling should be carried out in a well-ventilated hood.

Dissolve it in acetone, filter and precipitate it by adding Et2O.