HOME

TheInfoList



OR:

The Reed reaction is a
chemical reaction A chemical reaction is a process that leads to the IUPAC nomenclature for organic transformations, chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the pos ...
that utilizes
light Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 tera ...
to
oxidize Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a d ...
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 ex ...
s to alkyl
sulfonyl chloride In inorganic chemistry, sulfonyl halide groups occur when a sulfonyl () functional group is singly bonded to a halogen atom. They have the general formula , where X is a halogen. The stability of sulfonyl halides decreases in the order fluorides ...
s. This reaction is employed in modifying polyethylene to give
chlorosulfonated polyethylene Hypalon is a chlorosulfonated polyethylene (CSPE) synthetic rubber (CSM) noted for its resistance to chemicals, temperature extremes, and ultraviolet light. It was a product of DuPont Performance Elastomers, a subsidiary of DuPont. Hypalon as it i ...
(CSPE), which noted for its toughness.


Commercial implementations

Polyethylene is treated with a mixture of chlorine and sulfur dioxide under UV-radiation. Vinylsulfonic acid can also be prepared beginning with the sulfochlorination of
chloroethane Chloroethane, commonly known as ethyl chloride, is a chemical compound with chemical formula CH3CH2Cl, once widely used in producing tetraethyllead, a gasoline additive. It is a colorless, flammable gas or refrigerated liquid with a faintly sweet ...
.
Dehydrohalogenation In chemistry, dehydrohalogenation is an elimination reaction which removes a hydrogen halide from a substrate. The reaction is usually associated with the synthesis of alkenes, but it has wider applications. Dehydrohalogenation from alkyl halid ...
of the product gives vinylsulfonyl chloride, which subsequently is hydrolyzed to give
vinylsulfonic acid Vinylsulfonic acid is the organosulfur compound with the chemical formula CH2=CHSO3H. It is the simplest unsaturated sulfonic acid. The C=C double bond is a site of high reactivity. Polymerization gives polyvinylsulfonic acid, especially when ...
: :: ::= ::


Mechanism

The reaction occurs via a
free radical A daughter category of ''Ageing'', this category deals only with the biological aspects of ageing. Ageing Ailments of unknown cause Biogerontology Biological processes Causes of death Cellular processes Gerontology Life extension Metabo ...
mechanism. UV-light initiates homolysis of
chlorine Chlorine is a chemical element with the Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate betwee ...
, producing a pair of chlorine atoms: Chain initiation: ::::Cl2 -> \nu2Cl. Thereafter a chlorine atom attacks the hydrocarbon chain, freeing hydrogen to form
hydrogen chloride The compound hydrogen chloride has the chemical formula and as such is a hydrogen halide. At room temperature, it is a colourless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric water vapor. Hydrogen chloride ga ...
and an
alkyl In organic chemistry, an alkyl group is an alkane missing one hydrogen. The term ''alkyl'' is intentionally unspecific to include many possible substitutions. An acyclic alkyl has the general formula of . A cycloalkyl is derived from a cycloalk ...
free radical. The resulting radical then captures SO2. The resulting
sulfonyl In organosulfur chemistry, a sulfonyl group can refer either to a functional group found primarily in sulfones, or to a substituent obtained from a sulfonic acid by the removal of the hydroxyl group, similarly to acyl groups. Sulfonyl groups c ...
radical Radical may refer to: Politics and ideology Politics *Radical politics, the political intent of fundamental societal change *Radicalism (historical), the Radical Movement that began in late 18th century Britain and spread to continental Europe and ...
attacks another chlorine molecule to produce the desired sulfonyl chloride and a new chlorine atom, which continues the reaction chain. Chain propagation steps: :::: + .Cl -> + HCl :::: + SO2 -> R-\dotO2 :::: + Cl2 -> + Cl.


See also

*
Chain reaction A chain reaction is a sequence of reactions where a reactive product or by-product causes additional reactions to take place. In a chain reaction, positive feedback leads to a self-amplifying chain of events. Chain reactions are one way that syst ...


Historical readings

* Reed, C. F. ; ; . * * * *


References

Substitution reactions Carbon-heteroatom bond forming reactions Name reactions {{reaction-stub