Inorganic Thiocyanates

Inorganic thiocyanate is also known as rhodanide. It is the anion (SCN)^– and conjugate base of thiocyanic acid. Common derivatives include the colorless salts, such as potassium thiocyanate and sodium thiocyanate. Thiocyanates (SCN)^– are resonance stabilized such that the sulfur or nitrogen can act as a nucleophile, a metal ligand, and serve as linkage isomers. It is an ambidentate ligand; (SCN)^– can also bridge two (M-SCN-M) or even three metals. The Thiocyanate ion forms a complex with Fe³⁺ ions in solution, turning the solution into a blood red color.

Thiocyanate has the property of being a competitive inhibitor of the thyroid sodium-iodide symporter. It is used as a precursor for the synthesis of pharmaceuticals and other specialty chemicals. For example, it is employed to convert alkyl halides into the corresponding alkyl thiocyanates. It can act as a chaotropicagent, hence it can be used as a destaining agent. The chemical industry uses the thiocyante reagent to produce photographs and textiles.