肼

肼 is also known as diamide. Molecular formula N2H4, molecular weight 32.05, structurally simple H2N-NH2. A colorless oily liquid with a pungent odor similar to ammonia. It is highly toxic! It is mainly absorbed by the percutaneous, respiratory, and digestive tract and has a strong corrosive effect on the skin and mucous membranes. The temperature of 2 ° C, the boiling point of 113.5 ° C, the density (15 / 4 ° C) 1.011g / cm3. It absorbs water and carbon dioxide in the air and emits smoke. Miscible with water, methanol, ethanol, etc. Formed with a constant boiling point mixture with water, boiling point of 120.3 ° C, at this time containing 肼 68.5% by weight. Do not dissolve in ether, chloroform and benzene. If a small amount of air or metal ions are used during distillation or when it is irradiated with ultraviolet rays, it can cause an explosion. It has a purple flame when burned. Strong reduction. Can corrode glass, rubber, leather, cork, etc. It is alkaline and can react with inorganic acids to form salts. Used as a deoxidizer for high-pressure boiler feed water, it is replacing the sodium sulfite used in the past for pharmaceuticals such as synthetic amine urea, isoniazid, isonicotinyl, anti-tuberculosis drugs, pesticides (maleic acid hydrazide, germination inhibitor) , nitrofurazone and the like. Used as a phase sensitizer, antioxidant, reducing agent, etc., also used as a foaming agent; also used as a jet fuel, rocket fuel. In the plastics, rubber, photographic equipment, pharmaceutical, pesticide, textile, welding and other industries as a chemical raw material, as well as for boiler water deoxidation and corrosion. It can be prepared by the action of sodium hydroxide, chlorine and ammonia (or urea) in an aqueous solution, or by distillation of a hydrazine hydrate and a dehydrating agent such as sodium hydroxide, or by a hydrazine salt by aminolysis. In order to obtain anhydrous hydrazine, a dehydrating agent is added to the concentrate of hydrazine hydrate, and sodium hydroxide, potassium hydroxide, lime, etc., which are used as a dehydrating agent, must be distilled in an inert gas or in a vacuum. Toxicity: Mice were orally administered with LD5059 mg/kg (body weight) and rats at 60 mg/kg (body weight). Guinea pigs were percutaneous LD50190 mg/kg (body weight) and rabbits were 91 mg/kg (body weight). The mice were inhaled for 4 hours at a half-lethal concentration of 252 ppm and rats at 570 ppm. It is highly irritating to the eyes, nose and respiratory tract and damages the central nervous system. Acute poisoning first has local irritation, nausea, vomiting, followed by lethargy, ataxia, and even convulsions and coma. Some patients have liver damage. Mice can cause lung tumors by oral administration, and rats can cause liver tumors. The International Agency for Research on Cancer (1ARC) lists human suspected chemical carcinogens (insufficient evidence). The United States (ACGIH) specifies a threshold of 0.1 mg/m3 in the air of the workshop. The Soviet Union stipulated that the maximum allowable concentration in the air of the workshop was 0.1 mg/m3. Bismuth and its methyl derivatives are mixed with fuming nitric acid or dinitrogen tetroxide as a storable propellant for use in launch vehicles. Terpenes and amines form a mixed amine fuel (MAF), and several different terpenoids are combined into a mixed fuel (MHF), both of which are used as propellants. Bismuth and its derivatives are widely used in industrial production, such as in organic synthesis as intermediates, as well as in pharmaceutical and synthetic dyes. The combination of hydrazine and water is called hydration hydrazine. 40% hydrazine hydrate is commonly used in industry, which is safer than anhydrous hydrazine. It is also used as boiler water and some sewage treatment agents. Bismuth and its methyl derivatives are highly hygroscopic, easily absorb carbon dioxide from the air to form salts, leading to precipitation, and can be slowly oxidized in the presence of oxygen. The liquid reacts violently with the oxidant or metal oxide, and can spontaneously ignite or even explode. An explosive agent such as hydrazine mixed with nitromethane is more dangerous than trinitrotoluene. Its ammonia smell makes people alert in time, but it is not easy to detect at low concentrations. It can be stored for a long time under the condition that the container is filled with nitrogen. Osmium, dimethyl hydrazine and benzoquinone are moderately toxic, and methyl quinone is highly toxic. There was little difference in toxicity between intravenous and intraperitoneal injections and oral administration. High and moderate concentrations of guanidine, methyl guanidine and dimethyl hydrazine are highly irritating to the eyes, nose and respiratory tract, which are unacceptable at the lower limit of the explosion limit (2%). Direct contamination of the skin can cause dermatitis and can also sensitize. Liquid splashing into the eye can cause severe irritation, permanent damage to the cornea, and even blindness.