1,2-Dichloroethene, commonly called 1,2-dichloroethylene or 1,2-DCE, is the name for a pair of
organochlorine compounds with the molecular formula CHCl. They are both colorless liquids with a sweet odor. It can exist as either of two
geometric isomers
Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is ...
, ''cis''-1,2-dichloroethene or ''trans''-1,2-dichloroethene, but is often used as a mixture of the two. They have modest solubility in water. These compounds have some applications as a degreasing solvent.
In contrast to most
''cis-trans'' compounds, the ''Z'' isomer (''cis'') is more stable than the ''E'' isomer (''trans'') by 0.4 kcal/mol.
Production and use
''cis''-DCE, the ''Z'' isomer, is obtainable by the controlled
chlorination Chlorination may refer to:
* Chlorination reaction
In chemistry, halogenation is a chemical reaction that entails the introduction of one or more halogens into a compound. Halide-containing compounds are pervasive, making this type of transform ...
of
acetylene
Acetylene (systematic name: ethyne) is the chemical compound with the formula and structure . It is a hydrocarbon and the simplest alkyne. This colorless gas is widely used as a fuel and a chemical building block. It is unstable in its pure ...
:
:CH + Cl → CHCl
Industrially both isomers arise as byproducts of the production of
vinyl chloride
Vinyl chloride is an organochloride with the formula H2C=CHCl. It is also called vinyl chloride monomer (VCM) or chloroethene. This colorless compound is an important industrial chemical chiefly used to produce the polymer polyvinyl chloride (PVC ...
, which is produced on a vast scale. Unlike vinyl chloride, the 1,2-dichloroethylene isomers do not polymerize.
[
''trans''-DCE has applications including electronics cleaning, precision cleaning, and certain metal cleaning applications.
]
Reactions
Both isomers participate in Kumada coupling
In organic chemistry, the Kumada coupling is a type of cross coupling reaction, useful for generating carbon–carbon bonds by the reaction of a Grignard reagent and an organic halide. The procedure uses transition metal catalysts, typically n ...
reactions. ''trans''-1,2-Dichloroethylene participates in cycloaddition reactions.
Safety
These compounds have "moderate oral toxicity to rats".[
]
Environmental aspects
The dichloroethylene isomers occur in some polluted waters and soils. Significant attention has been paid to their further degradation, e.g. by iron particles.
See also
* 1,1-Dichloroethene
1,1-Dichloroethene, commonly called 1,1-dichloroethylene or vinylidene chloride or 1,1-DCE, is an organochloride with the molecular formula CHCl. It is a colorless liquid with a sharp odor. Like most chlorocarbons, it is poorly soluble in water, ...
* 1,2-Dichloroethane
The chemical compound 1,2-dichloroethane, commonly known as ethylene dichloride (EDC), is a chlorinated hydrocarbon. It is a colourless liquid with a chloroform-like odour. The most common use of 1,2-dichloroethane is in the production of vinyl ...
, which is also often abbreviated as 1,2-DCA
References
External links
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{{DEFAULTSORT:Dichloroethene, 1, 2-
Organochlorides
Haloalkenes
Halogenated solvents