Aliphatic compound

From Wikipedia, the free encyclopedia
(Redirected from Aliphatic)
Jump to navigation Jump to search
Acyclic aliphatic/non-aromatic compound (butane)
Cyclic aliphatic/non-aromatic compound (cyclobutane)

In organic chemistry, hydrocarbons (compounds composed solely of carbon and hydrogen) are divided into two classes: aromatic compounds and aliphatic compounds (/ˌælɪˈfætɪk/; G. aleiphar, fat, oil). Aliphatic compounds can be saturated (in which all the C-C bonds are single, requiring the structure to be completed, or 'saturated', by hydrogen) like hexane, or unsaturated, like hexene and hexyne. Open-chain compounds, whether straight or branched, and which contain no rings of any type, are always aliphatic. Cyclic compounds can be aliphatic if they are not aromatic.[1]

Structure

[edit | edit source]

Aliphatic compounds can be saturated, joined by single bonds (alkanes), or unsaturated, with double bonds (alkenes) or triple bonds (alkynes). If other elements (heteroatoms) are bound to the carbon chain, the most common being oxygen, nitrogen, sulfur, and chlorine, it is no longer a hydrocarbon, and therefore no longer an aliphatic compound. However, such compounds may still be referred to as aliphatic if the hydrocarbon portion of the molecule is aliphatic, e.g. aliphatic amines, to differentiate them from aromatic amines.

The least complex aliphatic compound is methane (CH4).

Properties

[edit | edit source]

Most aliphatic compounds are flammable, allowing the use of hydrocarbons as fuel, such as methane in natural gas for stoves or heating; butane in torches and lighters; various aliphatic (as well as aromatic) hydrocarbons in liquid transportation fuels like petrol/gasoline, diesel, and jet fuel; and other uses such as ethyne (acetylene) in welding.

Examples of aliphatic compounds

[edit | edit source]

The most important aliphatic compounds are:

  • n-, iso- and cyclo-alkanes (saturated hydrocarbons)
  • n-, iso- and cyclo-alkenes and -alkynes (unsaturated hydrocarbons).

Important examples of low-molecular aliphatic compounds can be found in the list below (sorted by the number of carbon-atoms):

Formula Name Structural formula Chemical classification
CH4 Methane Alkane
C2H2 Acetylene Alkyne
C2H4 Ethylene Alkene
C2H6 Ethane Alkane
C3H4 Propadiene File:Structural formula of propadiene.svg Diene
C3H4 Propyne File:Propyne-2D-flat.png Alkyne
C3H6 Propylene File:Propene Structural Formula V1.svg Alkene
C3H8 Propane File:Propan Lewis.svg Alkane
C4H6 1,2-Butadiene File:Buta-1,2-dien.svg Diene
C4H6 1-Butyne File:Ethylacetylene.svg Alkyne
C4H8 1-Butene File:1-Butene.svg Alkene
C4H10 Butane Error creating thumbnail: Alkane
C5H12 Pentane File:Pentan Skelett.svg Alkane
C6H10 Cyclohexene File:Cyclohexen - Cyclohexene.svg Cycloalkene
C6H12 Cyclohexane File:Cyclohexane simple.svg Cycloalkane
C6H14 Hexane File:Hexan Skelett.svg Alkane
C7H14 Methylcyclohexane File:Methylcyclohexane.svg Cycloalkane
C8H8 Cubane File:Cuban.svg Prismane, Platonic hydrocarbon
C8H18 Octane File:Octan Skelett.svg Alkane
C10H12 Dicyclopentadiene File:Di-Cyclopentadiene ENDO & EXO V.2.svg Diene, Cycloalkene
C10H16 Terpinene File:Alpha-Terpinene.svgFile:Beta-Terpinene.svg Terpene, Diene, Cycloalkene
C10H16 Phellandrene File:Phellandrene alpha.svgFile:Phellandrene beta.svg Terpene, Diene, Cycloalkene
C10H16 Limonene File:(R)-Limonen.svgFile:(S)-Limonen.svg Terpene, Diene, Cycloalkene
C10H22 Decane File:Decan Skelett.svg Alkane
C30H50 Squalene File:Squalene.svg Terpene, Polyene
C2nH4n Polyethylene File:Polyethylene repeat unit.svg Alkane

References

[edit | edit source]
  1. ^ IUPAC, Compendium of Chemical Terminology, 5th ed. (the "Gold Book") (2025). Online version: (1995) "aliphatic compounds". Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).

Lua error in Module:Authority_control at line 153: attempt to index field 'wikibase' (a nil value).