Sulfonyl halide groups occur when a sulfonyl

Sulfonyl

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...

 functional group

Functional group

In organic chemistry, functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. The same functional group will undergo the same or similar chemical reaction regardless of the size of the molecule it is a part of...

 is singly bonded to a halogen

Halogen

The halogens or halogen elements are a series of nonmetal elements from Group 17 IUPAC Style of the periodic table, comprising fluorine , chlorine , bromine , iodine , and astatine...

 atom

Atom

The atom is a basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons. The atomic nucleus contains a mix of positively charged protons and electrically neutral neutrons...

. They have the general formula R-SO₂-X where X is a halogen.

Sulfonyl fluorides

Sulfonyl fluorides have the general formula R-SO₂-F and can be important sulfonyl halide synthetic precursor

Precursor (chemistry)

In chemistry, a precursor is a compound that participates in the chemical reaction that produces another compound. In biochemistry, the term "precursor" is used more specifically to refer to a chemical compound preceding another in a metabolic pathway....

s. For example, "most, if not all" industrially synthesized perfluorooctanesulfonyl derivatives, such as PFOS, have the sulfonyl fluoride as their precursor.

Sulfonyl chlorides

Sulfonic acid chlorides, or sulfonyl chlorides, are a sulfonyl halide with the general formula R-SO₂-Cl. These compounds react readily with nucleophiles like alcohol

Alcohol

In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....

s and amine

Amine

Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines,...

s (see Hinsberg reaction

Hinsberg reaction

The Hinsberg reaction is a chemical test for the detection of amines.It is an excellent test for distinguishing primary,secondary and tertiary amines.In this test, the amine is shaken well with Hinsberg reagent in the presence of aqueous alkali . A reagent containing an aqueous sodium hydroxide...

). If the nucleophile is an alcohol the product is a sulfonic ester, if it is an amine the product is a sulfonamide. Important sulfonic acid chlorides are tosyl

Tosyl

A tosyl group is CH3C6H4SO2. This group is usually derived from the compound 4-toluenesulfonyl chloride, CH3C6H4SO2Cl, which forms esters and amides of toluenesulfonic or tosylic acid...

 chloride, brosyl chloride, nosyl chloride and mesyl

Mesylate

In chemistry, a mesylate is any salt or ester of methanesulfonic acid . In salts, the mesylate is present as the CH3SO3− anion. When modifying the International Nonproprietary Name of a pharmaceutical substance containing the group or anion, the correct spelling is mesilate .Mesylate esters are a...

 chloride. One synthetic procedure to synthesize sulfonic acid chlorides is the Reed reaction

Reed reaction

The Reed reaction is a chemical reaction that utilizes light to oxidize hydrocarbons to sulfonyl chlorides. The reaction performs via the free radicals. First, the light makes a molecule of chlorine dissociate homolytically, then an chlorine atom produced attacks the hydrocarbon chain to form...

. Sulfonyl chloride is very prone to hydrolysis. An ice/water bath can be used to decrease this effect (Titus 1982 & Lefevre 1996).

In popular culture

In the episode "Encyclopedia Galactica" of his TV series Cosmos: A Personal Voyage

Cosmos: A Personal Voyage

Cosmos: A Personal Voyage is a thirteen-part television series written by Carl Sagan, Ann Druyan, and Steven Soter, with Sagan as presenter. It was executive-produced by Adrian Malone, produced by David Kennard, Geoffrey Haines-Stiles and Gregory Andorfer, and directed by the producers, David...

, Carl Sagan

Carl Sagan

Carl Edward Sagan was an American astronomer, astrophysicist, cosmologist, author, science popularizer and science communicator in astronomy and natural sciences. He published more than 600 scientific papers and articles and was author, co-author or editor of more than 20 books...

 speculates that some intelligent extraterrestrial beings might have a genetic code

Genetic code

The genetic code is the set of rules by which information encoded in genetic material is translated into proteins by living cells....

 based on polyaromatic sulfonyl halides instead of DNA

DNA

Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...

.