Hydroxylamine is an inorganic substance with chemical formula HthreeNO or NHtwoOH[3], unstable white large or needle shaped crystals.It is easy to absorb moisture and dissolve in water.Decomposed in hot water, slightly soluble inEther, benzenecarbon disulfide、chloroform。The melting point is 32.05 ℃, and the boiling point is 70 ℃ (1.33kPa).
Unstable, absorbs water vapor andcarbon dioxideIt can be decomposed rapidly.It explodes violently when heated.Easily soluble in water, liquid nitrogen and methanol.
Hydroxylamine is irritating to the respiratory system, skin, eyes and mucous membrane, harmful if swallowed, and is a potential mutagen.
Unstable white large or needle shaped crystals.It is easy to absorb moisture and dissolve in water.When the concentration is 100%, 10%, 20%, 30%, 40% and 50%, the relative density of the aqueous solution is 1.2040, 1.0192, 1.0410, 1.0637, 1.0875 and 1.1122 respectively.The product decomposes in hot water and is slightly soluble inEther, benzenecarbon disulfide、chloroform。The melting point is 32.05 ℃, and the boiling point is 70 ℃ (1.33kPa).[1]
Preparation method
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1. UseHydroxylamine alcohol hydrochlorideSolution additionSodium ethoxideThe precipitated sodium chloride is quickly filtered out, the filtrate is cooled to - 18 ℃ for crystallization, filtered, and hydroxylamine is obtained.takeHydroxylamine phosphateThe crude hydroxylamine can also be obtained by heating distillation (operating at 1.73kPa) and collecting 135-137 ℃ fractions.
2. There are two methods to prepare hydroxylamine, one is to heat and decompose some hydroxylamine compounds, the other isHydroxylamine hydrochlorideReaction with sodium alkoxide.Fill 70g (1mol) of dry hydroxylamine hydrochloride 0.02g of phenolphthalein and 100mL of butanol into a three neck flask with agitator, drip funnel and outlet pipe.After stirring for 10min, drop sodium butanol (23.5g of metal sodium and 300mL of butanol are used in advance, and prepared by heating in a flask with reflux condenser) from the dropping funnel and stir strongly.The dropping speed shall be such that the indicator does not leave any color.Remove NaCl by suction filtration.Wash once with 15mL butanol, and then useAnhydrous ethanolWash for 3~4 times (the solubility of hydroxylamine can be reduced by adding ether), and transfer the filtrate into the flask with grinding mouth to seal it.Cool to - 10 ℃, let hydroxylamine precipitate and crystallize, filter and use pre cooledAnhydrous etherwash.21.0g (63.5% of the theoretical amount) of the product can be obtained and sealed for storage.A heating tube is designed outside the drip funnel to prevent the curing of the reagent inside.[1]
The research team of Professor Zeng Jie and Professor Geng Zhigang from the University of Science and Technology of China has developed a new and sustainable way to successfully synthesize hydroxylamine.They first efficiently convert air and water into high-purity nitric acid by means of plasma discharge, and then use the electro catalytic process to reduce nitric acid to produce hydroxylamine with high selectivity under mild conditions.On April 19, 2024, this achievement was published in the internationally authoritative journal Nature · Sustainability.[4]
Unstable, absorbs water vapor and CO at room temperaturetwoIt can be decomposed rapidly.It explodes violently when heated.Easily soluble in water, liquid nitrogen and methanol.
Hydroxylamine is irritating to the respiratory system, skin, eyes and mucous membrane, harmful if swallowed, and is a potential mutagen.[2]
Oxime is usually a solid with fixed melting point, and its formation and decomposition reaction can be used for purificationCarbonyl compound。DimethylglyoximeIsoximes are also commonly used ligand reagents.
The hydroxylamine-O-sulfonic acid should be stored at 0 ° C, and also usedIodometryTo determine the purity.
Reduction of hydroxylamine and its derivatives (R-NHOH) to obtainamine：
NHtwoOH (Zn/HCl) → NHthree
R-NHOH (Zn/HCl) → R-NHtwo
Hydroxylamine can interact with metal ionsCoordinationAnd the resulting complex hasBonded isomerism：M ←NHtwoOH and M ←ONHthree。[2]
purpose
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Used in organic synthesisreducing agent；Condensation with carbonyl compounds to form oximes (manyoximeFor indicators such asDimethylglyoximeIt is used to test nickel ion, and formaldehyde oxime is used to test manganese ion).
Hydroxylamine can be specifically cleavedAsparagineAnd glycine (Asn Gly).The peptide bond (Asn Pro) between asparagine and proline is broken under acidic conditions.The peptide bond between asparagine and leucine (Asn Leu) and the peptide bond between asparagine and alanine (Asn Ala) can also be partially cleaved.[2]
Storage and transportation conditions
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The warehouse is ventilated and dry at low temperature;Store separately from combustibles.[2]
