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| Identifiers | |
|---|---|
3D model (JSmol) | |
| ChemSpider |
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| Properties | |
| −C5H11 | |
| Molar mass | 71.1408 g/mol |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Pentyl is a five-carbonalkyl group orsubstituent withchemical formula -C5H11. It is the substituent form of thealkanepentane.
In older literature, the common non-systematic nameamyl was often used for the pentyl group. Conversely, the namepentyl 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 inamobarbital.
Acyclopentyl group is a ring with the formula -C5H9.
The name is also used for thepentyl radical, a pentyl group as an isolated molecule. Thisfree radical is only observed in extreme conditions.[1] Its formula is often written "C
5H
11•" or "• C
5H
11" to indicate that it has one unsatisfiedvalence bond.Radicals like pentyl are reactive, they react with neighboring atoms or molecules (likeoxygen,water, etc.)
The following names are still used sometimes:
| Name | Structure | IUPAC status | IUPAC recomm. | Examples |
|---|---|---|---|---|
| n-pentyl,amyl | H 3C−(CH 2) 4− | pentyl | [2] | |
| tert-pentyl | H 3C−CH 2−(H 3C−) 2C− | No longer recommended[3] | 2-methylbutan-2-yl (aka 1,1-dimethylpropyl)[3] | [4] |
| neopentyl | (H 3C−) 3C−CH 2− | No longer recommended[3] | 2,2-dimethylpropyl[3] | [5] |
| isopentyl,amyl,isoamyl | (H 3C−) 2CH−(CH 2) 2− | No longer recommended[3] | 3-methylbutyl[3] | [6] |
| sec-pentyl | H 3C−(CH 2) 2−(H 3C−)CH− | pentan-2-yl[7](or (1-methylbutyl)) | [8] | |
| 3-pentyl | (H 3C−CH 2−) 2CH− | pentan-3-yl (also known as 1-ethylpropyl) | [9] | |
| sec-isopentyl | (H 3C−) 2CH−(H 3C−)CH− | 3-methylbutan-2-yl (or 1,2-dimethylpropyl) | ||
| active pentyl | H 3C−CH 2−(H 3C−)CH−CH 2− | 2-methylbutyl |
The free radical pentyl was studied by J. Pacansky and A. Gutierrez in 1983.[1] The radical was obtained by exposingbishexanoyl peroxide trapped in frozenargon toultraviolet light, that caused its decomposition into twocarbon dioxide (CO
2) molecules and two pentyl radicals.
