Carbohydrazide is the
chemical compound with the formula OC(N2H3)2. It appears as a white solid that is soluble in water,[1][2] but not in many organic solvents, such as ethanol, ether or benzene. It decomposes upon melting.[2] 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 with
hydrazine:[3]
OC(NH2)2 + 2 N2H4 → OC(N2H3)2 + 2 NH3
It can also be prepared by reactions of other C1-precursors with
hydrazine, such as
carbonate esters.[2]
It can be prepared from
phosgene, but this route cogenerates the
hydrazinium salt [N2H5]Cl and results in some diformylation. Carbazic acid is also a suitable precursor:
N2NH3CO2H + N2H4 → OC(N2H3)2 + H2O
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.[4]
Industrial uses
Oxygen scrubber: carbohydrazide is used to remove oxygen in boiler systems. Oxygen scrubbers prevent corrosion.[5][6]
Precursor to polymers: carbohydrazide can be used as a curing agent for epoxide-type resins.[2]
Photography: carbohydrazide 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.[2]
Jet fuel: carbohydrazine can be used as a component in jet fuels, as a large amount of heat is being produced when the material is burned.
Carbohydrazide has been used to develop ammunition propellants,[7] stabilize soaps,[2] and is used as a reagent in organic synthesis.
Salts of carbohydrazide, such as nitrate, dinitrate and perchlorate, can be used as secondary explosives.[8]Complex salts of carbohydrazide, like bis(carbohydrazide)diperchloratocopper(II) and tris(carbohydrazide)nickel(II) perchlorate, can be used as
primary explosives in
laser detonators.[9]
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.[10]
^
abcdefKurzer, Frederick; Michael Wilkinson (February 1970). "Chemistry of carbohydrazide and thiocarbohydrazide". Chemical Reviews. 70 (1): 111–149.
doi:
10.1021/cr60263a004.
PMID4391877.
^Jean-Pierre Schirmann, Paul Bourdauducq "Hydrazine" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2002.
doi:
10.1002/14356007.a13_177.
^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.
doi:
10.1107/S0567740879003575