Potassium thiocyanate
Encyclopedia
Potassium thiocyanate is the chemical compound
with the molecular formula KSCN. It is an important salt of the thiocyanate
anion, one of the pseudohalides. The compound has a low melting point relative to most other inorganic salts.
to give Pb(SCN)2, which has been used to convert acyl chloride
s to thiocyanates.
KSCN converts ethylene carbonate
to ethylenesulfide. For this purpose, the KSCN is first melted under vacuum to remove water. In a related reaction, KSCN converts cyclohexene oxide to the corresponding episulfide
.
KSCN is also the starting product for the synthesis of carbonyl sulfide
.
), the product of the reaction is a solution with a blood red colour, due to the formation of the thiocyanatoiron
complex ion. Thus this chemical is often used to create the effect of 'stigmata'. Because both solutions are colorless, they can be placed separately on each hand. When the hands are brought into contact, the solutions react and the effect looks remarkably like stigmata
.
Similarly, this reaction is used as a test for Fe3+ in the laboratory
.
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
with the molecular formula KSCN. It is an important salt of the thiocyanate
Thiocyanate
Thiocyanate is the anion [SCN]−. It is the conjugate base of thiocyanic acid. Common derivatives include the colourless salts potassium thiocyanate and sodium thiocyanate. Organic compounds containing the functional group SCN are also called thiocyanates...
anion, one of the pseudohalides. The compound has a low melting point relative to most other inorganic salts.
Use in chemical synthesis
Aqueous KSCN reacts almost quantitatively with Pb(NO3)2Lead(II) nitrate
Lead nitrate is an inorganic compound with the chemical formula Pb2. It commonly occurs as a colourless crystal or white powder and, unlike most other lead salts, is soluble in water....
to give Pb(SCN)2, which has been used to convert acyl chloride
Acyl chloride
In organic chemistry, an acyl chloride is an organic compound with the functional group -CO-Cl. Their formula is usually written RCOCl, where R is a side chain. They are usually considered to be reactive derivatives of carboxylic acids. A specific example of an acyl chloride is acetyl chloride,...
s to thiocyanates.
KSCN converts ethylene carbonate
Ethylene carbonate
Ethylene carbonate is an ester of ethylene glycol and carbonic acid. At room temperature ethylene carbonate is a transparent crystalline solid, practically odorless and colorless, and somewhat soluble in water. In the liquid state Ethylene carbonate is an ester of ethylene glycol and carbonic...
to ethylenesulfide. For this purpose, the KSCN is first melted under vacuum to remove water. In a related reaction, KSCN converts cyclohexene oxide to the corresponding episulfide
Episulfide
Episulfides are a class of organic compounds that contain a saturated heterocyclic ring consisting of two carbon atoms and one sulfur atom. It is the sulfur analogue of an epoxide or aziridine. They are also known as thiiranes, olefin sulfides, thioalkylene oxides, and thiacyclopropanes.The parent...
.
- C6H10O + KSCN → C6H10S + KOCNPotassium cyanatePotassium cyanate is an inorganic compound with the formula KOCN . 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.-Structure and bonding:Cyanate is isoelectronic with...
KSCN is also the starting product for the synthesis of carbonyl sulfide
Carbonyl sulfide
Carbonyl sulfide is the chemical compound with the formula OCS. Commonly written as COS, it is a colourless flammable gas with an unpleasant odor. It is a linear molecule consisting of a carbonyl group double bonded to a sulfur atom...
.
Other uses
Dilute aqueous KSCN is occasionally used for moderately realistic blood effects in film and theater. It can be painted onto a surface or kept as a colorless solution. When in contact with ferric chloride solution (or other solutions containing Fe3+Ferric
Ferric refers to iron-containing materials or compounds. In chemistry the term is reserved for iron with an oxidation number of +3, also denoted iron or Fe3+. On the other hand, ferrous refers to iron with oxidation number of +2, denoted iron or Fe2+...
), the product of the reaction is a solution with a blood red colour, due to the formation of the thiocyanatoiron
Thiocyanatoiron
Thiocyanatoiron is a complex ion with the chemical formula [FeSCN]2+. It is known to produce a blood red color in solution. This is used as a test for Fe3+ in the laboratory...
complex ion. Thus this chemical is often used to create the effect of 'stigmata'. Because both solutions are colorless, they can be placed separately on each hand. When the hands are brought into contact, the solutions react and the effect looks remarkably like stigmata
Stigmata
Stigmata are bodily marks, sores, or sensations of pain in locations corresponding to the crucifixion wounds of Jesus, such as the hands and feet...
.
Similarly, this reaction is used as a test for Fe3+ in the laboratory
Laboratory
A laboratory is a facility that provides controlled conditions in which scientific research, experiments, and measurement may be performed. The title of laboratory is also used for certain other facilities where the processes or equipment used are similar to those in scientific laboratories...
.