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Thiocyanate complexes are not widely used commercially. Possibly the oldest application of thiocyanate complexes was the use of thiocyanate as a test for ferric ions in aqueous solution. [14] The reverse was also used: testing for the presence of thiocyanate by the addition of ferric salts. The 1:1 complex of thiocyanate and iron is deeply red.
Thiocyanate used to be known as rhodanide (from a Greek word for rose) because of the red colour of its complexes with iron. Thiocyanate is produced by the reaction of elemental sulfur or thiosulfate with cyanide: + + + The second reaction is catalyzed by thiosulfate sulfurtransferase, a hepatic mitochondrial enzyme, and by other sulfur ...
The article hemoglobin incorrectly states that oxyhemoglogin contains iron(III). It is now known that the iron(II) in hemoglobin is a low-spin complex, whereas in oxyhemoglobin it is a high-spin complex. The low-spin Fe 2+ ion fits snugly into the cavity of the porphyrin ring, but high-spin iron(II) is significantly larger and the iron atom is ...
Thiocyanate is a common test for the presence of iron(III) as it forms the blood-red [Fe(SCN)(H 2 O) 5] 2+. Like manganese(II), most iron(III) complexes are high-spin, the exceptions being those with ligands that are high in the spectrochemical series such as cyanide. An example of a low-spin iron(III) complex is [Fe(CN) 6] 3−.
Mercury(II) thiocyanate (Hg(SCN) 2) is an inorganic chemical compound, the coordination complex of Hg 2+ and the thiocyanate anion. It is a white powder. It is a white powder. It will produce a large, winding "snake" when ignited, an effect known as the Pharaoh's serpent .
It is formed when an oxygen is singly bonded to the thiocyanate group. Hypothiocyanous acid is a fairly weak acid; its acid dissociation constant (pK a) is 5.3. Hypothiocyanite is formed by peroxidase [1] catalysis of hydrogen peroxide and thiocyanate: H 2 O 2 + SCN − → OSCN − + H 2 O
Aryl thiocyanates are traditionally produced by the Sandmeyer reaction, which involves combining copper(I) thiocyanate and diazonium salts: [3] [ArN 2 ]BF 4 + CuSCN → ArSCN + CuBF 4 + N 2 Some arylthiocyanates can also often be obtained by thiocyanogenation , i.e. the reaction of thiocyanogen .
When the energy difference between the high-spin and low-spin states is comparable to kT (k is the Boltzmann constant and T the temperature) an equilibrium is established between the spin states, involving what have been called "electronic isomers". Tris-dithiocarbamato iron(III), Fe(S 2 CNR 2) 3, is a well-documented example.