What Is Hydroxylamine Hydrochloride?
Hydroxylamine hydrochloride is the hydrochloride salt of hydroxylamine.
A highly concentrated solution of hydroxylamine can react with itself or with iron ions, leading to explosions. It should, therefore, be transported and used in a diluted state; concentrations below 15% are considered safe.
Hydroxylamine is classified as a priority chemical substance and a hazardous material under various safety laws.
Uses of Hydroxylamine Hydrochloride
In organic synthesis, hydroxylamine hydrochloride is used to synthesize oximes and hydroxamic acids from carboxylic acids, and N- and O-hydroxylamines. It is also utilized in carbon-carbon double bond (C=C) addition reactions.
Industrially, it serves to remove bromine during the extraction of lignin from biomass. It acts as a surface treatment agent in paints and semiconductors and as a raw material for pharmaceuticals and agrochemicals. In the rubber and plastics industries, it is employed as an antioxidant, vulcanization accelerator, and radical scavenger. It contributes to the production of nylon and is used as a fixative in textile dyeing, a dyeing aid, an antioxidant, and a dye-fixing agent in color films.
Hydroxylamine hydrochloride is significant in the nitrogen cycle and wastewater treatment, functioning as a biological intermediate in nitrification and anaerobic ammonia oxidation.
Properties of Hydroxylamine Hydrochloride
Hydroxylamine hydrochloride appears as a white crystal. It is readily soluble and ranks among the strongest reducing agents. It dissolves in water and exhibits strong acidity, gradually decomposing in aqueous solutions and moist air. It is also soluble in liquid ammonia, slightly soluble in methanol and ethanol, but insoluble in ether.
It poses an explosion hazard near fire or heat sources and may explode if heated above 115°C. It decomposes at 152°C and can form oximes with aldehydes and ketones. Hydroxylamine hydrochloride is also a precursor to hydroxylamine.
Structure of Hydroxylamine Hydrochloride
Hydroxylamine hydrochloride, with the chemical formula [NH3OH]Cl, has a molecular weight of 69.49 g/mol and a density of 1.68 g/cm3. The bond distance between nitrogen and oxygen (N-O) is approximately 1.45 Å. It is known by other names such as hydroxyamine hydrochloride, and hydroxylammonium chloride, and is a monoclinic and ionic crystal containing [NH3OH]+ ions.
Hydroxylamine hydrochloride is produced through the reaction of nitric acid with HCl following electrolytic reduction, or from the reaction of BaCl2 with aqueous hydroxylammonium sulfate.
Other Information About Hydroxylamine Hydrochloride
1. Related Compounds to Hydroxylamine Hydrochloride
Hydroxylamine is typically managed as an aqueous solution or as hydroxylamine hydrochloride. Its empirical formula is NH2OH, sharing structural characteristics with both ammonia and water.
Its molecular weight is 33.030 g/mol, with a melting point of 33°C, decomposing at 58°C, and a density of 1.21 g/cm3 at 20°C. Hydroxylamine, at room temperature, is a crystalline solid and exhibits hygroscopic and deliquescent properties.
2. Hydroxylamine Salts
Hydroxylamine salts result from the neutralization of hydroxylamine with acids. Beyond hydroxylamine hydrochloride, these include hydroxylamine sulfate.
The chemical formula for hydroxylamine sulfate is H2SO4・(NH2OH)2, with a molecular weight of 164.14 g/mol. It decomposes at 170°C, appearing as a white crystal, soluble in water and strongly acidic.