Chemistry:Carbazide

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Carbohydrazide
Carbohydrazide, the simplest carbazide
Diphenylcarbazide
Diphenylcarbazide

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 of carbonic acid with a hydrazine. Carbohydrazide is the simplest carbazide, with another common carbazide being diphenylcarbazide, which is used as an analytical reagent.[1]

Diphenylcarbazide 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 is called a thiocarbazide, of which thiocarbohydrazide 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 is an example.

See also

References

  1. Crossley, H. E. (1936). "Diphenylcarbazide. An internal indicator for use in the titration of iron with dichromate". The Analyst 61 (720): 164. doi:10.1039/AN9366100164. Bibcode1936Ana....61..164C.