Hydroxylamine
General
Systematic name	hydroxylamine
Molecular formula	NH2OH
Molar mass	33.0298 g/mol
Appearance	white needles or flakes
CAS number	7803-49-8
Properties
Density and phase	1.21g cm−3
Solubility in water	soluble in cold water, decomposes in hot water
Solubility in other solvents	soluble in methanol, liquid NH3 slightly soluble in ether, benzene, chloroform, carbon disulfide Image File history File links Size of this preview: 724 × 600 pixelsFull resolution (1100 × 911 pixel, file size: 169 KB, MIME type: image/png) File historyClick on a date/time to view the file as it appeared at that time. ... Image File history File links Size of this preview: 745 × 599 pixelsFull resolution (1100 × 885 pixel, file size: 24 KB, MIME type: image/png) File historyClick on a date/time to view the file as it appeared at that time. ... IUPAC nomenclature is a system of naming chemical compounds and of describing the science of chemistry in general. ... This article or section does not cite any references or sources. ... This article does not cite any references or sources. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... For other uses, see Density (disambiguation). ... In the physical sciences, a phase is a set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties (i. ... It has been suggested that this article or section be merged with Solution. ... H2O and HOH redirect here. ... It has been suggested that this article or section be merged with Solution. ...
Melting point	33 °C
Boiling point	110 °C
Structure
Dipole moment	0.67553 debye
Thermodynamic data
Standard enthalpy of formation	−39.9 kJ/mol
Standard molar entropy	? J K−1 mol−1
Hazards
EU classification	Symbol: Xn, N R: 5-22-37/38-41-43-48/22-50 The melting point of a crystalline solid is the temperature range at which it changes state from solid to liquid. ... Italic text This article is about the boiling point of liquids. ... The Earths magnetic field, which is approximately a dipole. ... The standard enthalpy of formation or standard heat of formation of a compound is the change of enthalpy that accompanies the formation of 1 mole of a substance in its standard state from its constituent elements in their standard states (the most stable form of the element at 1 atmosphere... In chemistry, the standard molar entropy is the entropy content of one mole of substance, under conditions of standard temperature and pressure. ... Council Directive 67/548/EEC of 27 June 1967 on the approximation of laws, regulations and administrative provisions relating to the classification, packaging and labelling of dangerous substances (as amended) is the main European Union law concerning chemical safety. ... S: (2-)-22-26-36/37/39-61
NFPA 704	3 3 1
Supplementary data page
Spectral data	UV, IR, NMR, MS
Related compounds
Related compounds	Hydroxylamine hydrochloride Hydroxylamine sulfate NFPA 704 is a standard maintained by the U.S. National Fire Protection Association. ... Image File history File links NFPA_704. ... Ultraviolet-Visible Spectroscopy or Ultraviolet-Visible Spectrophotometry (UV/ VIS) involves the spectroscopy of photons (spectrophotometry). ... Infrared spectroscopy (IR Spectroscopy) is the subset of spectroscopy that deals with the IR region of the EM spectrum. ... Nuclear magnetic resonance spectroscopy most commonly known as NMR spectroscopy is the name given to the technique which exploits the magnetic properties of certain nuclei. ... Mass spectrometry (also known as mass spectroscopy (deprecated)[1] or informally, mass-spec and MS) is an analytical technique used to measure the mass-to-charge ratio of ions. ...
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Hydroxylamine is a reactive chemical with formula NH₂OH. It can be considered a hybrid of ammonia and water due to parallels it shares with each. At room temperature pure NH₂OH is ordinarily a white, unstable crystalline, hygroscopic compound; ^[1] however it is almost always encountered as an aqueous solution. In chemistry, the standard state of a material is its state at 1 bar (100 kilopascals) and 25 degrees Celsius (298. ... This article or section does not cite any references or sources. ... For other uses, see Ammonia (disambiguation). ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... For other uses, see Crystal (disambiguation). ... A hygroscopic substance is a substance that absorbs water readily from its surroundings. ...

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. ^[2] 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. This article is concerned solely with chemical explosives. ... For other uses, see Iron (disambiguation). ... For other uses, see Salt (disambiguation). ...

NH₂OH is an intermediate in biological nitrification. The oxidation of NH₃ is mediated by HAO (hydroxylamine oxidoreductase). Nitrogen cycle Nitrification is the biological oxidation of ammonia with oxygen into nitrite followed by the oxidation of these nitrites into nitrates. ...

Production

NH₂OH can be synthesized 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. Ammonium nitrite, NH4NO2, is formed by oxidizing ammonia with ozone or hydrogen peroxide; using precipitations from reacting barium or lead nitrites with ammonium sulfate, or silver nitrite with ammonium chloride. ...

NH₄NO₂ + 2SO₂ + NH₃ + H₂O → [NH₄]₂[N(OH)(OSO₂)₂]

[NH₄]⁺₂[N(OH)(OSO₂)₂]²⁻ + H₂O → [NH₄][NH(OH)(OSO₂)] + [NH₄][HSO₄]

2[NH₄]⁺[NH(OH)(OSO₂)]⁻ + 2H₂O → [NH₃(OH)]₂[SO₄] + [NH₄]₂[SO₄]

Solid NH₂OH can be collected by treatment with liquid ammonia. Ammonium sulfate is insoluble in liquid ammonia and is removed by filtration; the liquid ammonia is evaporated to give the desired product.^[1] Ammonium sulphate, [NH4]2[SO4] contains 21% nitrogen as ammonia and 24% sulfur as sulfate. ... For other uses, see Ammonia (disambiguation). ...

Another method of synthesis is to make hydroxylammonium salts which can then be converted to hydroxylamine.

[NH₃(OH)]Cl + NaOBu → NH₂OH + NaCl + BuOH^[1]

The reduction of nitrous acid or potassium nitrate with bisulfite: Nitrous acid (molecular formula HNO2) is a weak monobasic acid known only in solution and in the form of nitrite salts. ... R-phrases   S-phrases   Supplementary data page Structure and properties n, εr, etc. ... The bisulfite ion is the HSO3- ion. ...

HNO₂ + 2 HSO₃⁻ → [N(OH)(OSO₂)₂]²⁻ + H₂O → [NH(OH)(OSO₂)]⁻ + [HSO₄]⁻

[NH(OH)(OSO₂)]⁻ + H₃O⁺ (100 °C/1 h) → [NH₃(OH)]⁺ + [HSO₄]⁻

Reactions

Hydroxylamine reacts with electrophiles, such as an alkylating agents, which can attack at either the O or N position. In chemistry, an electrophile (literally electron-lover) is a reagent attracted to electrons that participates in a chemical reaction by accepting an electron pair in order to bond to a nucleophile. ... Alkylating agents are so named because of their ability to add alkyl groups to many electronegative groups under conditions present in cells. ...

R-X + NH₂OH → R-ONH₂ + HX

R-X + NH₂OH → R-NHOH + HX

The reaction of NH₂OH with an aldyhyde or ketone produces an oxime. An oxime is one in a class of chemical compounds with the general formula R1R2 C N O H, where R1 is an organic side chain and R2 is either hydrogen, forming an aldoxime, or another organic group, forming a ketoxime. ...

R₂C=O + NH₂OH∙HCl , NaOH → R₂C=NOH + NaCl + H₂O

This reaction is useful in the purification of ketones and aldehydes, Oximes also are employed as ligands, e.g. dimethylglyoxime. An oxime is one in a class of chemical compounds with the general formula R1R2CNOH, where R1 is an organic side chain and R2 is either hydrogen, forming an aldoxime, or another organic group, forming a ketoxime. ... In chemistry, a ligand is an atom, ion, or molecule (see also: functional group) that generally donates one or more of its electrons through a coordinate covalent bond to, or shares its electrons through a covalent bond with, one or more central atoms or ions (these ligands act as a... This page is a candidate to be copied to Wiktionary. ...

NH₂OH reacts with chlorosulfuric acid to give hydroxylamine-O-sulfonic acid, a useful reagent for the synthesis of caprolactam. Caprolactam (C6H11ON) is the monomer used in the production of nylon 6. ...

HOSO₂Cl + NH₂OH → NH₂OS₂OH + HCl

The hydroxylamine-O-sulfonic acid, which should be stored at 0 °C, can checked by iodometric titration.

Hydroxylamine (NH₂OH), or hydroxylamines (R-NHOH) can be reduced to amines.^[3] The general structure of an amine Amines are organic compounds and a type of functional group that contain nitrogen as the key atom. ...

NH₂OH (Zn/HCl) → NH₃

R-NHOH (Zn/HCl) → R-NH₂

Uses

Hydroxylamine 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.^[4]

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. Hydroxylammonium Nitrate or hydroxylamine Nitrate (HAN) is an energetic chemical with the chemical formula NH3OHNO3. ... A (usually liquid) rocket propellant that can be used by itself, without the need for a second component. ... The Space Shuttle is initially launched with the help of solid-fuel boosters A Solid rocket or a solid fuel rocket is a rocket with a motor that uses solid propellants (fuel/oxidizer). ...

This has also been used in the past by biologists to introduce random mutations by switching base pairs from A to G, or from C to T. This is to probe functional areas of genes to elucidate what happens if their functions are broken. Nowadays other mutagens are used. Hydroxylamine can also be used to highly selectively cleave asparaginyl-glycine peptide bonds in peptides and proteins. It also bonds to and permanently disables (poisons) heme-containing enzymes. It is used as an irreversible inhibitor of the oxygen-evolving complex of photosynthesis on account of its similar structure to water. For other articles using the abbreviation or acronym asn see ASN. Asparagine is one of the 20 most common natural amino acids on Earth. ... For the plant, see Glycine (plant). ... A hemoprotein (also haemoprotein), or heme protein, is a metalloprotein containing a heme prosthetic group, either covalently or noncovalently bound to the protein itself. ... Oxygen evolving complex. ...

In the semiconductor industry, hydroxylamine is often a component in the "resist stripper" which removes photoresist after lithography.

Safety

Hydroxylamine 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.^[5]

References

External links

• Calorimetric studies of hydroxylamine decomposition
• Chemical company BASF info
• MSDS
• MSDS
• Deadly detonation of hydroxylamine at Concept Sciences facility