Language
Country/Area
No result found
The Journey of Discovering Hydrohydrazine: What's the Story Behind Its Naming?
Hydrazine is an inorganic compound with the chemical formula N2H4. It is a colorless, flammable liquid with an ammonia-like odor. Hydrohydrazine is extremely hazardous unless handled in solution, such as hydrohydrazine hydrate (N2H4·xH2O). Typically, hydrohydrazine is used as a blowing agent and plays an important role in preparing polymer foams. It is also used as a precursor for pharmaceuticals and pesticides, and as a long-term storage propellant in spacecraft propulsion systems. Hydrohydrazine also has applications in various rocket fuels and can be used to prepare gaseous precursors for airbags.
"Hydrazine may not be widely known, as it has uses in aerospace and chemical industries, but its history and development has been full of challenges and innovations."
Naming and History
The name "hydrazine" was first proposed by Emil Fischer in 1875, who was trying to create organic compounds consisting of monosubstituted hydrazines. By 1887, Theodor Curtius had produced hydrazine sulfate by treating an organic dinitride with dilute sulfuric acid, but despite repeated attempts he was unable to obtain pure hydrazine. It was not until 1895 that Dutch chemist Lobry de Bruyn prepared anhydrous hydrazine for the first time. The naming convention comes from the prefix "hydr-" indicating the presence of hydrogen atoms, and the suffix "-az-" comes from the French word for nitrogen (azote).
Application of Hydrohydrazine
Gas Generation and Propellants
The largest use of hydrohydrazine is as a precursor of blowing agents. Certain compounds, such as azide dicarbonamide and azidoisobutyronitrile, can produce 100-200 ml of gas per gram of precursor. Related to this application, hydrohydrazine is also used in the production of sodium azide, a gas generating agent in airbags. Additionally, hydrohydrazine is used as a propellant for long-term storage on spacecraft, and during the Dawn mission, it was used to explore the asteroids Ceres and Asteroid Ceres.
Pesticide and pharmaceutical precursors
Hydrazine is also a precursor of many medicines and pesticides. These applications generally involve the conversion of hydrohydrazines into heterocyclic compounds such as pyrazoles and pyridines. Commercialized biologically active hydrazine derivatives include cefuroxime, retatriptan, anastrozole, etc., and play an important role in pesticides.
Small scale, niche markets and research
Italian catalyst manufacturer Acta has proposed using hydrohydrazine as a replacement for hydrogen as part of a fuel cell. The main advantages of using hydrohydrazine are that it does not require expensive platinum catalysts and can produce powers in excess of 200 mW/cm², and that it is liquid at room temperature, making it easier to store and handle than hydrogen.
"As efforts to find an alternative to hydrohydrazine intensify, the future of this compound may be uncertain."
Occupational hazards
Health EffectsPotential routes of exposure to hydrohydrazine include skin, eyes, inhalation, and ingestion. Exposure to hydrohydrazine may cause symptoms such as skin irritation, eye burns, and breathing difficulties. During exposure, damage to the liver, kidneys, and central nervous system may occur. Hydrochloric acid is considered a strong skin allergen and may cause cross-sensitization to hydrochloric acid derivatives.
Occupational Exposure Limits
The occupational exposure limits for hydrohydrazine include 0.03 ppm recommended by NIOSH and 1 ppm (8-hour average) acceptable by OSHA. In the aerospace field, there are specific guidelines for exposure limits especially for emergency situations.
Synthesis and manufacture of hydrohydrazine
Hydrazine can be produced by a variety of routes, including methods that use chlorine oxidants and methods that do not use chlorine oxidants. The earliest process dates back to the Orin Rashige process in 1907, which used sodium hypochlorite and ammonia. Among the different methods for synthesizing hydrohydrazine, the oxidation process of hydrogen peroxide is a relatively widely used preparation route.
"The synthesis of hydrohydrazine is not only a chemical adventure, but also a key link in industrial application."
Sharing and reflection
Since its discovery, hydrohydrazine has experienced a period of ups and downs in both its scientific background and industrial applications. From the earliest chemical reactions to current space exploration, hydrazine has become an indispensable component in many fields due to its unique properties. But with the advancement of technology and the rise of environmental awareness, how long can the role of hydrohydrazine last in the future?
