In chemistry, a carbazide is a
functional group with the general formula RNH-NH(C=O)NH-NHR. They can be derived from the
condensation
Condensation is the change of the state of matter from the gas phase into the liquid phase, and is the reverse of vaporization. The word most often refers to the water cycle. It can also be defined as the change in the state of water vapor to ...
of
carbonic acid with a
hydrazine
Hydrazine is an inorganic compound with the chemical formula . It is a simple pnictogen hydride, and is a colourless flammable liquid with an ammonia-like odour. Hydrazine is highly toxic unless handled in solution as, for example, hydrazine ...
.
Carbohydrazide
Carbohydrazide is the chemical compound with the formula OC(N2H3)2. It is a white, water-soluble solid. It decomposes upon melting. A number of carbazides are known where one or more N-H groups are replaced by other substituents. They occur wi ...
is the simplest carbazide, with another common carbazide being diphenylcarbazide, which is used as an analytical reagent.
Diphenylcarbazide
1,5-Diphenylcarbazide (or simply Diphenylcarbazide, often abbreviated DPC) is a chemical compound from the group of the carbazides. It has a structural formula similar to that of diphenylcarbazone and can be easily converted into it by oxidatio ...
forms an intense blue color with chromium in the hexavalent state. It has an
absorptivity coefficient of about 3400. That means very small amounts of chromium can be detected; 25 micrograms in 25 mL of solution are too dark to read on a spectral device, so concentrations well below that can be detected.
Thiocarbazide
The sulfur
analog
Analog or analogue may refer to:
Computing and electronics
* Analog signal, in which information is encoded in a continuous variable
** Analog device, an apparatus that operates on analog signals
*** Analog electronics, circuits which use analo ...
is called a thiocarbazide, of which
thiocarbohydrazide
Thiocarbohydrazide is a toxic compound made by the reaction of carbon disulfide with hydrazine (hydrazinolysis). It is used in the silver proteinate specific staining of carbohydrates in electron microscopy
An electron microscope is a microsc ...
is the simplest example.
Carbazone and thiocarbazone
A carbazone is a partially
oxidized carbazide with the general formula R=NNH(C=O)NH-NHR. The sulfur analog is called a thiocarbazone, of which
dithizone
Dithizone is a sulfur-containing organic compound. It is a good ligand, and forms complexes with many toxic metals such as lead, thallium and mercury.
Dithizone may be prepared by reacting phenylhydrazine with carbon disulfide, followed by react ...
is an example.
See also
* Semicarbazide
* Semicarbazone
References
{{reflist
Hydrazides
Functional groups