Carbohydrazide is the
chemical compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...
with the formula OC(N
2H
3)
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 widely in the drugs, herbicides, plant growth regulators, and dyestuffs.
Production
Industrially the compound is produced by treatment of
urea
Urea, also known as carbamide, is an organic compound with chemical formula . This amide has two amino groups (–) joined by a carbonyl functional group (–C(=O)–). It is thus the simplest amide of carbamic acid.
Urea serves an important ...
with
hydrazine:
[Jean-Pierre Schirmann, Paul Bourdauducq "Hydrazine" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2002. .]
:OC(NH
2)
2 + 2 N
2H
4 → OC(N
2H
3)
2 + 2 NH
3
It can also be prepared by reactions of other C1-precursors with
hydrazine, such as
carbonate ester
In organic chemistry, a carbonate ester (organic carbonate or organocarbonate) is an ester of carbonic acid. This functional group consists of a carbonyl group flanked by two alkoxy groups. The general structure of these carbonates is and they ...
s.
It can be prepared from
phosgene, but this route cogenerates the
hydrazinium
Hydrazinium is the cation with the formula . This cation has a methylamine-like structure (). It can be derived from hydrazine by protonation (treatment with a strong acid). Hydrazinium is a weak acid with p''K''a = 8.1.
Salts of hydrazinium ar ...
salt
2H5l and results in some diformylation. Carbazic acid is also a suitable precursor:
:N
2NH
3CO
2H + N
2H
4 → OC(N
2H
3)
2 + H
2O
Structure
The molecule is nonplanar. All nitrogen centers are at least somewhat pyramidal, indicative of weaker C-N pi-bonding. The C-N and C-O distances are about 1.36 and 1.25 Å, respectively.
[Ottersen, T.; Hope, H. "The Structure and Electron Deformation Density Distribution of Carbonohydrazide (Carbohydrazide) at 85 K" Acta Crystallographica B 1979, volume 35, p373-p378. ]
Industrial uses
* Oxygen scrubber: carbohydrazide is used to remove oxygen in boiler systems. Oxygen scrubbers prevent corrosion.
* Precursor to polymers: carbohydrazide can be used as a curing agent for epoxide-type resins.
* Photography: carbohyrazide is used in the silver halide diffusion process as one of the toners. Carbohydrazide is used to stabilize color developers that produce images of the azo-methine and azine classes.
* Carbohydrazide has been used to develop ammunition propellants,
stabilize soaps,
and is used as a reagent in organic synthesis.
Hazards
Heating carbohydrazide may result in an explosion. Carbohydrazide is harmful if swallowed, irritating to eyes, respiratory system, and skin. Carbohydrazide is toxic to aquatic organisms.
References
{{Hydrazines
Cleaning product components
Hydrazides