Hydrazine
NAME: Hydrazine
ALTERNATIVE NAME: H2NNH2
LANGUAGE: International
TIME: 19th century to present day
LOCATION: Laboratory
CATEGORY: Chemical
DISCIPLINE: Chemistry and industry
SHORT DESCRIPTION:
A colourless liquid belonging to the group of hydrogen-nitrogens compounds which is used in various industrial processes.
DESCRIPTION:
Hydrazine: discovered by <discovered by> Curtius* and first produced as a water solution and some solid salts towards the end of the nineteenth century.
A few years later, in 1894, pure hydrazine was made for the first time. It is soluble in water and some alcohols but will not dissolve in benzene or ether. It burns easily in air
and has a strong smell, like ammonia. Hydrazine vapour mixed with air can be violently explosive.
It is also a strong reducing agent which can convert the oxides of numerous metals to the free element. It is corrosive to most metals, with the exception of stainless steel and silver. It is also corrosive to rubber and most plastics, with the exception of polyethylene and Teflon.
For industrial use today, hydrazine is produced mainly by the Raschig process: sodium hypochlorite acts on excess ammonia in the presence of colloidal material. This forms a water solution which is distilled and dehydrated to isolate hydrazine.
One of the main industrial uses of hydrazine is as an oxygen scavenger in boilers operating at high pressures. When oxygen reacts with hydrazine, hydrogen peroxide is always formed and an aqueous solution is formed. It is therefore useful as an anti-corrosive which removes the oxygen in boiler feedwater, while at the same time producing no increase in the solid content of the water.
The other main use of hydrazine is in rocketry, where it is combined with oxidising agents and used as a high energy fuel. During the second world war (1939-45) hydrazine was used to fuel the rockets of early German fighter planes, and a hydrazine sulphate salt, oxidised by hydrogen sulphate, was used to propel torpedoes.
Hydrazine was developed for rocket fuel by <as fuel by> Karman.* A form of hydrazine is used to fuel the Space Shuttle orbiter maneuvering engines, and the Hubble Space Telescope positional thrusters. In more recent times, the mononitrate hydrazine salt has been used as a high explosive.
Hydrazine is also used to silver mirrors and to produce metal films on glass and plastics.
A mixture of hydrazine with copper compounds is used in fungicides first developed in the nineteenth century by the French botanist <fungicide first developed by> Millardet* against <fungicide against> phylloxera*.
Organic derivatives of hydrazine are used in analytical chemistry, as a treatment for tuberculosis and in the production of organic substances such as plastic resins, photographic chemicals and blowing agents for plastic foams.
Hydrazines are part of many organic syntheses, often those of practical significance in pharmaceuticals (see applications section), as well as in textile dyes and in photography.[9]
The largest use of hydrazine is as a precursor to blowing agents. Specific compounds include azodicarbonamide and azobisisobutyronitrile, which produce 100–200 mL of gas per gram of precursor. In a related application, sodium azide, the gas-forming agent in air bags, is produced from hydrazine by reaction with sodium nitrite.[9]
Hydrazine is also used as a long-term storable propellant on board space vehicles, such as the Dawn mission to Ceres and Vesta, and to both reduce the concentration of dissolved oxygen in and control pH of water used in large industrial boilers. The F-16 fighter jet, Eurofighter Typhoon,[10] Space Shuttle, and U-2 spy plane use hydrazine to fuel their Emergency Start System in the event of an engine stall.[11]
Extra Connections:
The name "hydrazine" was coined by Emil Fischer in 1875; he was trying to produce organic compounds that consisted of mono-substituted hydrazine.[63] By 1887, Theodor Curtius had produced hydrazine sulfate by treating organic diazides with dilute sulfuric acid; however, he was unable to obtain pure hydrazine, despite repeated efforts.[64][65][66] Pure anhydrous hydrazine was first prepared by the Dutch chemist Lobry de Bruyn in 1895.
It has two main properties that make it useful. First, it's a strong reducing agent, with often the only by-products being water and nitrogen. As such it is used to reduce plutonium oxides in nuclear waste back to Pu metal, and is added to the water-cooling systems of power stations to stop the pipes corroding/oxidising. It does this by scavenging dissolved oxygen, which would otherwise attack the metal.
N2H4 + O2 
N2 + 2H2O.
It's also used as a precursor for some organic syntheses, and in applications as diverse as fuel cells, a catalyst for polymerisation, solder fluxes and in photographic developing fluid. It's also used to make some of the precursors required in the polymerisation reaction that produces spandex (Lycra) fibres, something for which sportspeople, glam-rockers, and wannabe superheroes should be grateful.
The X-15 reaction control system (RCS), for maneuvering in the low-pressure/density environment, used high-test peroxide (HTP), which decomposes into water and oxygen in the presence of a catalyst and could provide a specific impulse of 140 s (1.4 km/s).[11][15] The HTP also fueled a turbopump for the main engines and auxiliary power units (APUs).[10]
ONELINER: Hydrazine, fungicide and rocket fuel
BIBLIOGRAPHY:
Encyclopedia Britannica
Reed, R A, ed., Hydazine and its Derivatives, in Lectures, Monographs and Reports. The Royal Institute of Chemistry, London, 1956.
See also *Kursk* submarine disaster (2000)
2. History of Isoniazid
Thinking on another line, let us review the history of Isoniazid development (Isonicotinylhydrazine) a hydrazine group member as the first line anti tubercular medication, in the prevention and treatment of tuberculosis. Hydrazines have their origins as expressed in the research carried out by Hermann Emil Fischer in 1870s (Figure 1).
Hermann Emil Fischer (Chemistry Nobel Prize, 1902)
He accidentally discovered Phenylhydrazine in 1874, while he was working in the laboratory of Adolf von Baeyer in Strasbourg, on hydrazine hydrate (a powerful reducing agent)....
For almost 40 years the hydrazines were forgotten. In the late forties its tuberculostatic effects were found unexpectedly during an in vivo random screening, i.e. in mice infected with tubercle Bacilli. The discovery of the anti-tubercular effects of this hydrazine derivative, which took place in 1951, is due to the independent research carried out, by two scientific teams, led by Herbert Hyman Fox of Hoffmann-La Roche Laboratories (Nutley, New Jersey) and Harry L. Yale of the Squibb Institute for Medical Research (Princeton, New Jersey), respectively.
In a research on anti-infectious drugs at the Squibb, hundreds of compounds were synthesized and studied on mice infected with Mycobacterium tuberculosis. In 1951, one of the chemists Harry Yale, synthesized a hydrazide intermediary (isonicotinyl-hydrazine), from isonicotinyl-aldehyde-thiosemicarbazon. The tuberculostatic efficacy of thiosemicarbazones had already been shown.
However, there was enormous surprise when the synthetic intermediate (isonicotinyl-hydrazine i.e. INH), was found to have greater antitubercular activity in animal model than the final product (isonicotinyl-aldehyde-thiosemicarbazon). After this discovery, clinical trials were conducted with this compound almost immediately in different hospitals in New York State; its antitubercular effectiveness was demonstrated, and the molecule is known as isoniazid (3).
The idea behind the history of Isoniazid is the speed of research, which took place after the discovery of its tuberculostatic property. Within two years, this drug was available for clinical use. Before that, only streptomycin was used against tuberculosis, but the development of drug resistance lowered its effectiveness. The discovery of Isoniazid established a combined drug regimen, necessary for effective treatment against tuberculosis....