Hydroxylamine
Oxyammoniak
- H3NO ( hydroxylamine )
- H3NO · HCl ( hydroxylamine · hydrochloride)
- 7803-49-8 ( hydroxylamine )
- 5470-11-1 ( hydroxylamine · hydrochloride)
Hygroscopic, odorless and colorless plates or needles
1.22 g · cm -3 ( 14 ° C)
- 33 ° C ( Hydroxylamine )
- 151 ° C ( hydroxylamine · hydrochloride)
- 159 ° C ( · hydroxylamine hydrochloride) (decomposition)
58 ° C (29 mbar)
1.9 hPa ( 20 ° C)
- 8.20 ( NH3OH / NH2OH )
- 13.70 ( NH2OH/NHOH- )
- Soluble in water ( 560 g / l of hydroxylamine ) and ethanol
- Very soluble in water, soluble in methanol
- Insoluble in benzene and chloroform
Risk
Template: Infobox chemical / molecular formula search available
Hydroxylamine is a colorless, crystalline inorganic chemical compound that was first synthesized by Cornelis Adriaan Lobry van Troostenburg de Bruyn.
Synthesis
Hydroxylamine by reduction of higher oxidation states of nitrogen (NO, NO2 -, NO3 - ) with hydrogen, sulfurous acid or electricity produced. Hydroxylamine is prepared industrially by passing a mixture of nitrogen monoxide and hydrogen in a sulfuric acid slurry of a catalyst ( palladium or platinum ) on activated carbon, the yield is 90% with this method.
Another technical approach is the introduction of sulfur dioxide in a solution of ammonium nitrite in sulfuric acid at 0 to 5 ° C. This first einsteht Diammoniumhydroxylaminbis ( sulfonate) N ( SO3NH4 ) 2OH, which slowly splits at 100 ° C by water in hydroxylamine and hydrogen sulfate. Also in this method, the yield is about 90%.
Another technical method is the reduction of nitric acid with an electric current, wherein, a solution of nitric acid in 50% sulfuric acid is used.
Responsiveness
Under exclusion of air hydroxylamine is several weeks. As an aqueous solution, it is quite stable under exclusion of air. In the presence of atmospheric oxygen hydroxylamine decomposes very rapidly both as a pure substance or as a solution above 70 ° C, the decomposition is done explosively.
Because of its instability hydroxylamine usually in its salts (for example, hydroxylamine hydrochloride, hydroxylamine sulfate ) is converted.
The relatively high melting and boiling points of hydroxylamine can be firstly by H- bonding, on the other hand by the partial tautomerization to amine oxide ionic charges carries explain. In addition, hydroxylamine is light as ampholyte.
Mutagenic effect
Hydroxylamine converts cytosine to uracil by hydrolysis. But uracil pairs with adenine in contrast to cytosine, which is why the CG base pair transforms after two replications to TA. Since uracil but does not occur in the DNA, such errors can be easily detected and corrected.
Use
The largest part of the hydroxylamine industrially produced is reacted with aldehydes or ketones to oximes. 97% of the world's annual production of hydroxylamine is used for the recovery of cyclohexanone oxime from cyclohexanone is converted into caprolactam Perlon. See the article on the Beckmann rearrangement.