Aziridine is an

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. T ...

consisting of the three-membered

heterocycle A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and ...

. It is a colorless, toxic, volatile liquid that is of significant practical interest. Aziridine was discovered in 1888 by the chemist

Siegmund Gabriel Siegmund Gabriel (7 November 1851 – 22 March 1924) was a German chemist. Scientific career Siegmund Gabriel began studying chemistry at the University of Berlin in 1871. He continued his studies at the University of Heidelberg in 1872 wi ...

. Its derivatives, also referred to as

aziridines 220 px, chemotherapeutic agent by virtue of its antitumour activity. Aziridines are organic compounds containing the aziridine functional group, a three-membered heterocycle with one amine (-NR-) and two methylene bridges (--). The parent compou ...

, are of broader interest in medicinal chemistry.

Structure

The

bond angle Bond or bonds may refer to: Common meanings * Bond (finance), a type of debt security * Bail bond, a commercial third-party guarantor of surety bonds in the United States * Chemical bond, the attraction of atoms, ions or molecules to form chemical ...

s in aziridine are approximately 60°, considerably less than the normal

hydrocarbon In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic, and their odors are usually weak or ...

bond angle of 109.5°, which results in

angle strain In organic chemistry, ring strain is a type of instability that exists when bonds in a molecule form angles that are abnormal. Strain is most commonly discussed for small rings such as cyclopropanes and cyclobutanes, whose internal angles are ...

as in the comparable cyclopropane and

ethylene oxide Ethylene oxide is an organic compound with the formula . It is a cyclic ether and the simplest epoxide: a three-membered ring consisting of one oxygen atom and two carbon atoms. Ethylene oxide is a colorless and flammable gas with a faintly sw ...

molecules. A

banana bond In organic chemistry, a bent bond, also known as a banana bond, is a type of covalent chemical bond with a geometry somewhat reminiscent of a banana. The term itself is a general representation of electron density or configuration resembling a ...

model explains bonding in such compounds. Aziridine is less basic than acyclic

aliphatic In organic chemistry, hydrocarbons ( compounds composed solely of carbon and hydrogen) are divided into two classes: aromatic compounds and aliphatic compounds (; G. ''aleiphar'', fat, oil). Aliphatic compounds can be saturated, like hexane, ...

amines, with a pKa of 7.9 for the

conjugate acid A conjugate acid, within the Brønsted–Lowry acid–base theory, is a chemical compound formed when an acid donates a proton () to a base—in other words, it is a base with a hydrogen ion added to it, as in the reverse reaction it loses a ...

, due to increased s character of the

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

free electron pair In chemistry, a lone pair refers to a pair of valence electrons that are not shared with another atom in a covalent bondIUPAC '' Gold Book'' definition''lone (electron) pair''/ref> and is sometimes called an unshared pair or non-bonding pair. Lo ...

Angle strain In organic chemistry, ring strain is a type of instability that exists when bonds in a molecule form angles that are abnormal. Strain is most commonly discussed for small rings such as cyclopropanes and cyclobutanes, whose internal angles are ...

in aziridine also increases the barrier to

nitrogen inversion In chemistry, pyramidal inversion (also umbrella inversion) is a fluxional process in compounds with a pyramidal molecule, such as ammonia (NH3) "turns inside out". It is a rapid oscillation of the atom and substituents, the molecule or ion passi ...

. This barrier height permits the isolation of separate ''invertomers'', for example the ''cis'' and ''trans'' invertomers of ''N''-chloro-2-methylaziridine.

Synthesis and uses

Aziridine is produced industrially from

aminoethanol Aminoethanol may refer to: * 1-Aminoethanol * Ethanolamine (2-aminoethanol, ETA, or MEA) {{Short pages monitor