Hydroxylamine
Encyclopedia : H : HY : HYD : Hydroxylamine
| Hydroxylamine | |
|---|---|
 
| |
| General | |
| Systematic name | hydroxylamine |
| Molecular formula | NH2OH |
| Molar mass | 33.0298 |
| Appearance | white needles or flakes |
| CAS number | however it is almost always encountered as an aqueous solution. Hydroxylamine tends to be explosive, and the nature of the hazard is not entirely understood. At least two factories dealing in hydroxylamine have been destroyed since 1999 with loss of life. It is known, however, that ferrous and ferric iron accelerate the decomposition of 50% NH2OH solutions. Hydroxylamine and its derivatives are more safely handled in the form of salts. NH2OH is an intermediate in the biological nitrification. The oxidation of NH3 is mediated by HAO (hydroxylamine oxidoreductase).
ProductionNH2OH can be synthesizing via several routes:Raschig synthesis: Aqueous ammonium nitrite is reduced by HSO4-/SO2 at 0 °C to yield a hydroxylamido-N,N-disulfate anion, which can be hydrolyzed to give (NH3OH)2SO4.
Another method of synthesis is to make hydroxylammonium salts which can then be converted to hydroxylamine. The reduction of nitrous acid or potassium nitrate with bisulfite:
ReactionsHydroxylamine reacts with electrophiles, such as an alkylating agents, which can attack at either the O or N position.
NH2OH reacts with chlorosulfuric acid to give hydroxylamine-O-sulfonic acid, a useful reagent for the synthesis of caprolactam.
Hydroxylamine (NH2OH), or hydroxylamines (R-NHOH) can be reduced to amines.[#endnote_reduce]
UsesHydroxylamine and its salts are commonly used as reducing agents in a myriad of organic and inorganic reactions. They can also act as antioxidants for fatty acids. Some non-chemical uses include removal of hair from animal hides and photography developing solutions.[#endnote_uses]The nitrate salt, hydroxylammonium nitrate, is being researched as a rocket propellant, both in water solution as a monopropellant and in its solid form as a solid propellant. This has also been used in the past by biologists to introduce random mutations in genomes which switch base pairs from A to G, or from C to T. This is to probe functional areas of genes to "see" what happens if their functions are broken. In recent times other methods of random mutations have been used. SafetyHydroxylamine may explode on heating. It is an irritant to the respiratory tract, skin, eyes, and other mucous membranes. It may be absorbed through the skin, is harmful if swallowed, and is a possible mutagen.[#endnote_safety]References↑ [Hydroxylamine] Walters, Michael A. and Andrew B. Hoem. "Hydroxylamine." e-Encyclopedia of Reagents for Organic Synthesis. 2001. ↑ Greenwood and Earnshaw. Chemistry of the Elements. 2nd Edition. Reed Educational and Professional Publishing Ltd. pp. 431-432. 1997. ↑ [MSDS] Sigma-Aldrich ↑ [Schupf Computational Chemistry Lab] ↑ Patnaik, Pradyot. Handbook of Inorganic Chemicals. McGraw Hill. pp. 385-386. 2003. ↑ Smith, Michael and Jerry March. March's advanced organic chemistry : reactions, mechanisms, and structure. New York. Wiley. p. 1554. 2001. M. W. Rathke A. A. Millard "Boranes in Functionalization of Olefins to Amines: 3-Pinanamine" Organic Syntheses, Coll. Vol. 6, p.943; Vol. 58, p.32. (preparation of hydroxylamine-O-sulfonic acid). External links
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