Carbohydrazide

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Carbohydrazide
Structural formula
Ball-and-stick model
Identifiers
CAS number 497-18-7 YesY
PubChem 73948
ChemSpider 66578 YesY
ChEBI CHEBI:61308 YesY
Jmol-3D images Image 1
Image 2
Properties
Molecular formula CH6N4O
Molar mass 90.09 g/mol
Density 1.341 g/cm3
Melting point 153 to 154 °C (307 to 309 °F; 426 to 427 K)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Carbohydrazide is used as an oxygen scavenger in water treatment for boilers. It is an alternative to the hazardous and potentially carcinogenic hydrazine. Carbohydrazide reacts with oxygen to make water, nitrogen and urea. It also passivates metals and reduces metal oxides converting ferric oxide to ferrous oxide and converting cupric oxide to cuprous oxide.

It is widely used in the production of drugs, herbicides, plant growth regulators, and dyestuffs.

Physical properties[edit]

Carbohydrazide is a white crystalline solid with a melting point of 153-154 °C.[1][2] It decomposes upon melting.[2] It is very water soluble and largely insoluble in organic solvents.[1][2]

Synthesis[edit]

Hydrazinolyis of carbonate esters:[2]

(C2H5O)2CO + 2N2H4•H20 → NH2NHCONHNH2 + 2C2H5OH + 2H2O

Hydrazinolysis of phosgene:[2]

ClCOCl + NH2NH2 → NH2NHCOCl
NH2NHCOCl + NH2NH2 → NH2NHCONHNH2
NH2NHCOCl + ClCOCl → ClCONHNHCOCl
ClCONHNHCOCl + NH2NH2 → NH2NHCONHNHCONHNH2

Hydrazinolysis of carbazic acid:[2]

NH2NHCOOH•NH2NH2 → NH2NHCONHNH2 + H2O

Industrial uses[edit]

  • Oxygen scrubber: carbohydrazide is used as an oxygen scrubber in boiler systems. Oxygen scrubbers remove oxygen gas from the boiler system to prevent corrosion.[3][4]
  • Polymers: carbohydrazide can react with many aromatic compounds to create polymers.[2] Carbohydrazide can be used as a curing agent for epoxide-type resins.[2]
  • 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.[2]
  • Carbohydrazide has been used to develop ammunition propellants,[5] stabilize soaps,[2] and used a reagent in organic synthesis.

Hazards[edit]

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.[6]

References[edit]

  1. ^ a b Inorganic Syntheses Volume IV. McGraw-Hill Book Company, Inc. 1953. p. 35. 
  2. ^ a b c d e f g h i j Kurzer, Frederick; Michael Wilkinson (February 1970). "Chemistry of carbohydrazide and thiocarbohydrazide". ACS Chemical Reviews. doi:10.1021/cr60263a004. 
  3. ^ Buecker, Brad (1997). Power Plant Water Chemistry A Practical Guide. PennWell Publishing Company. pp. 13–16. ISBN 0-87814-619-9. 
  4. ^ "Patent US4269717". Retrieved 8 October 2012. 
  5. ^ "Patent US2970899". Retrieved 8 October 2012. 
  6. ^ "MSDS". Retrieved 8 October 2012.