Ethylenediamine is the organic compound with the formula C2H42. This colorless liquid with an ammonia-like odor is a strongly basicamine. It is a widely used building block in chemical synthesis, with approximately 500,000 tonnes produced in 1998. Ethylenediamine readily reacts with moisture in humid air to produce a corrosive, toxic and irritating mist, to which even short exposures can cause serious damage to health. Ethylenediamine is the first member of the so-called polyethylene amines.
Synthesis
Ethylenediamine is produced industrially by treating 1,2-dichloroethane with ammoniaunder pressure at 180 °C in an aqueous medium: In this reaction hydrogen chloride is generated, which forms a salt with the amine. The amine is liberated by addition of sodium hydroxide and can then be recovered by. Diethylenetriamine and triethylenetetramine are formed as by-products. Another industrial route to ethylenediamine involves the reaction of ethanolamine and ammonia: This process involves passing the gaseous reactants over a bed of nickel heterogeneous catalysts. Ethylenediamine can be purified by treatment with sodium hydroxide to remove water followed by distillation.
Applications
Ethylenediamine is used in large quantities for production of many industrial chemicals. It forms derivatives with carboxylic acids, nitriles, alcohols, alkylating agents, carbon disulfide, and aldehydes and ketones. Because of its bifunctional nature, having two amines, it readily forms heterocycles such as imidazolidines.
Precursor to chelation agents, drugs, and agrochemicals
A most prominent derivative of ethylenediamine is the chelating agentEDTA, which is derived from ethylenediamine via a Strecker synthesis involving cyanide and formaldehyde. Hydroxyethylethylenediamine is another commercially significant chelating agent. Numerous bio-active compounds and drugs contain the N-CH2-CH2-N linkage, including some antihistamines. Salts of ethylenebisdithiocarbamate are commercially significant fungicides under the brand namesManeb, Mancozeb, Zineb, and Metiram. Some imidazoline-containing fungicides are derived from ethylenediamine.
Ethylenediamine, because it contains two amine groups, is a widely used precursor to various polymers. Condensates derived from formaldehyde are plasticizers. It is widely used in the production of polyurethane fibers. The PAMAM class of dendrimers are derived from ethylenediamine.
Tetraacetylethylenediamine
The bleaching activator tetraacetylethylenediamine is generated from ethylenediamine. The derivative N,N-ethylenebis is a commercially significant mold-release agent and a surfactant in gasoline and motor oil.
as a compound to sensitize nitromethane into an explosive. This mixture was used at Picatinny Arsenal during WWII, giving the nitromethane and ethylenediamine mixture the nickname PLX, or Picatinny Liquid Explosive.
Coordination chemistry
Ethylenediamine is a well-known bidentatechelating ligand for coordination compounds, with the two nitrogen atoms donating their lone pairs of electrons when ethylenediamine acts as a ligand. It is often abbreviated "en" in inorganic chemistry. The complex Triscobalt chloride|3+ is an archetypical chiral tris-chelate complex. The salen ligands, some of which are used in catalysis, are derived from the condensation of salicylaldehydes and ethylenediamine.
Ethylenediamine, like ammonia and other low-molecular weight amines, is a skin and respiratory irritant. Unless tightly contained, liquid ethylenediamine will release toxic and irritating vapors into its surroundings, especially on heating. The vapors react with moisture in humid air to form a characteristic white mist, which is extremely irritating to skin, eyes, lungs and mucus membranes.
