Inorganic chemistry, avinyl group (abbr.Vi;[1]IUPAC name:ethenyl group[2]) is afunctional group with the formula−CH=CH2. It is theethylene (IUPAC name: ethene) molecule (H2C=CH2) with one fewerhydrogen atom. The name is also used for any compound containing that group, namelyR−CH=CH2 where R is any other group of atoms.
An industrially important example isvinyl chloride, precursor toPVC,[3] a plastic commonly known asvinyl.
Vinyl is one of thealkenyl functional groups. On a carbon skeleton,sp2-hybridized carbons or positions are often calledvinylic.Allyls,acrylates andstyrenics contain vinyl groups. (A styrenic crosslinker with two vinyl groups is calleddivinyl benzene.)
Vinyl groups canpolymerize with the aid of a radical initiator or a catalyst, formingvinyl polymers. Vinyl polymers contain no vinyl groups. Instead they are saturated. The following table gives some examples of vinyl polymers.
| Monomer example | Example of resulting polymer |
|---|---|
| Vinyl chloride | Polyvinyl chloride (PVC) |
| Vinyl fluoride | Polyvinyl fluoride (PVF) |
| Vinyl acetate | Polyvinyl acetate (PVAc) |
Vinyl derivatives arealkenes. If activated by an adjacent group, the increased polarization of the bond gives rise to characteristic reactivity, which is termedvinylogous:
Vinyl organometallics, e.g.vinyllithium andvinyl tributyltin, participate invinylations including coupling reactions such as inNegishi coupling.
The radical was first reported byHenri Victor Regnault in 1835 and initially namedaldehydène. Due to the incorrect measurement of theatomic mass of carbon it was believed to beC4H6 at the time. Then in 1839 it was renamed byJustus von Liebig to "acetyl", because he believed it to be the radical of theacetic acid.[4]
The modern term was coined by German chemistHermann Kolbe in 1851, who rebutted Liebig's hypothesis.[5] However even in 1860Marcellin Berthelot still based the name he coined foracetylene on Liebig's nomenclature and not on Kolbe's.
Theetymology of "vinyl" is theLatinvinum = "wine", and theGreek word "hylos" 'υλος (matter or material), because of its relationship withethyl alcohol.