Pentyl group


title: "Pentyl group" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["alkyl-groups"] topic_path: "general/alkyl-groups" source: "https://en.wikipedia.org/wiki/Pentyl_group" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

|ImageFile = n-pentyl.png |ImageFile_Ref = |ImageName = Skeletal formula of pentyl with all explicit hydrogens added |Section1={{Chembox Identifiers |CASNo = 2672-01-7 |PubChem = 123167 |ChemSpiderID = 109782 |ChemSpiderID_Ref = |SMILES = [CH2]CCCC |StdInChI = 1S/C5H11/c1-3-5-4-2/h1,3-5H2,2H3 |StdInChI_Ref = |StdInChIKey = BFKVXNPJXXJUGQ-UHFFFAOYSA-N |StdInChIKey_Ref = |Section2={{Chembox Properties |Formula = |MolarMass = 71.1408 g/mol

Pentyl is a five-carbon alkyl group or substituent with chemical formula . It is the substituent form of the alkane pentane.

In older literature, the common non-systematic name amyl was often used for the pentyl group. Conversely, the name pentyl was used for several five-carbon branched alkyl groups, distinguished by various prefixes. The nomenclature has now reversed, with "amyl" being more often used to refer to the terminally branched group also called isopentyl, as in amobarbital.

A cyclopentyl group is a ring with the formula .

The name is also used for the pentyl radical, a pentyl group as an isolated molecule. This free radical is only observed in extreme conditions. Its formula is often written "•" or "• ⁠" to indicate that it has one unsatisfied valence bond. Radicals like pentyl are reactive, they react with neighboring atoms or molecules (like oxygen, water, etc.)

Older "pentyl" groups

The following names are still used sometimes: ::data[format=table]

NameStructureIUPAC statusIUPAC recomm.Examples
n-pentyl, amyl−−pentyl
tert-pentyl−−C−title = Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book)publisher = The Royal Society of Chemistrydate = 2014
neopentylC−−No longer recommended2,2-dimethylpropyl
isopentyl, amyl, isoamylCH−−No longer recommended3-methylbutyl
sec-pentyl−−(−)CH−title = Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book)publisher = The Royal Society of Chemistry
3-pentylCH−pentan-3-yl (also known as 1-ethylpropyl)
sec-isopentyl−CH−3-methylbutan-2-yl (or 1,2-dimethylpropyl)
active pentyl−−(−)CH−−2-methylbutyl
::

Pentyl radical

The free radical pentyl was studied by J. Pacansky and A. Gutierrez in 1983. The radical was obtained by exposing bishexanoyl peroxide trapped in frozen argon to ultraviolet light, that caused its decomposition into two carbon dioxide () molecules and two pentyl radicals.

Examples

References

References

  1. (2014). "Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book)". [[Royal Society of Chemistry.
  2. (2014). "Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book)". [[Royal Society of Chemistry.
  3. J. Pacansky, A. Gutierrez (1983), "Infrared spectra of the ''n''-butyl and ''n''-pentyl radicals". Journal of Physical Chemistry volume 87, issue 16, pages 3074–3079{{doi. 10.1021/j100239a023
  4. [http://www.ebi.ac.uk/chebi/searchId.do;4E388CA79B0FD418DBE11B5D9E965518?chebiId=CHEBI:30359 isopentyl group] at CHEBI. Accessed on 2013-02-21
  5. [http://www.ebi.ac.uk/chebi/searchId.do;09B55F14C1B445CFA9112CA4FD34E04F?chebiId=CHEBI:32881 Pentan-3-yl group] at CHEBI. Accessed on 2013-02-21
  6. [http://www.ebi.ac.uk/chebi/searchId.do?chebiId=55344 n-pentyl nitrite], described as "a nitrite ester having n-pentyl as the alkyl group." Accessed on 2013-02-21
  7. [http://www.ebi.ac.uk/chebi/searchId.do?chebiId=7983 Pentobarbital] at CHEBI, described as "Barbituric acid substituted at C-5 by ethyl and sec-pentyl groups". Accessed on 2013-02-21
  8. [http://www.ebi.ac.uk/chebi/searchId.do;C0C7CAEA43537B527A5F0550819A1D33?chebiId=CHEBI:30357 neopentyl] at CHEBI. Accessed on 2013-02-21
  9. NCBI, [https://pubchem.ncbi.nlm.nih.gov/compound/6405 ''tert''-pentyl alcohol] in PubChem. Accessed on 2013-02-21

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::

alkyl-groups