Thiosemicarbazide is the chemical compound with the formula H
2NC(S)NHNH
2. A white, odorless solid, it is related to
thiourea
Thiourea () is an organosulfur compound with the formula and the structure . It is structurally similar to urea (), with the oxygen atom replaced by sulfur atom (as implied by the '' thio-'' prefix). The properties of urea and thiourea differ s ...
(H
2NC(S)NH
2) by the insertion of an NH center. They are commonly used as
ligand
In coordination chemistry, a ligand is an ion or molecule with a functional group that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's el ...
s for transition metals. Many thiosemicarbazides are known. These feature an organic substituent in place of one or more H's of the parent molecule.
4-Methyl-3-thiosemicarbazide is a simple example.
According to
X-ray crystallography
X-ray crystallography is the experimental science of determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to Diffraction, diffract in specific directions. By measuring th ...
, the CSN
3 core of the molecule is almost planar as are the three H atoms nearest the
thiocarbonyl
In organic chemistry, thioketones (; also known as thiones or thiocarbonyls) are organosulfur compounds related to conventional ketones in which the oxygen has been replaced by a sulfur. Instead of a structure of , thioketones have the structure ...
group. This can be explained by models of electron delocalisation.
Reactions
Thiosemicarbazides are precursors to
thiosemicarbazones. They are precursors to
heterocycles. Formylation of thiosemicarbazide provides access to triazole.
References
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Thiosemicarbazones
Functional groups