This article relies largely or entirely on a single source. (October 2022) |
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.
Structure
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
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
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 | Propyne |  | Alkyne |
| C3H6 | Propene |  | Alkene |
| C3H8 | Propane |  | Alkane |
| C4H6 | 1,2-Butadiene |  | Diene |
| C4H6 | 1-Butyne |  | Alkyne |
| C4H8 | 1-Butene |  | Alkene |
| C4H10 | Butane |  | Alkane |
| C6H10 | Cyclohexene |  | Cycloalkene |
| C5H12 | n-pentane |  | Alkane |
| C7H14 | Cycloheptane |  | Cycloalkane |
| C7H14 | Methylcyclohexane |  | Cyclohexane |
| C8H8 | Cubane |  | Prismane, Platonic hydrocarbon |
| C9H20 | Nonane |  | Alkane |
| C10H12 | Dicyclopentadiene |  | Diene, Cycloalkene |
| C10H16 | Phellandrene |   | Terpene, Diene, Cycloalkene |
| C10H16 | α-Terpinene |  | Terpene, Diene, Cycloalkene |
| C10H16 | Limonene |   | Terpene, Diene, Cycloalkene |
| C11H24 | Undecane |  | Alkane |
| C30H50 | Squalene |  | Terpene, Polyene |
| C2nH4n | Polyethylene |  | Alkane |
References
- IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (1995) "aliphatic compounds". doi:10.1351/goldbook.A00217
 | This organic chemistry article is a stub. You can help Wikipedia by expanding it. |
This article relies largely or entirely on a single source Relevant discussion may be found on the talk page Please help improve this article by introducing citations to additional sources Find sources Aliphatic compound news newspapers books scholar JSTOR October 2022 In organic chemistry hydrocarbons compounds composed solely of carbon and hydrogen are divided into two classes aromatic compounds and aliphatic compounds ˌ ae l ɪ ˈ f ae t ɪ k 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 Acyclic aliphatic non aromatic compound butane Cyclic aliphatic non aromatic compound cyclobutane StructureAliphatic 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 PropertiesMost 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 compoundsThe 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 classificationCH4 Methane AlkaneC2H2 Acetylene AlkyneC2H4 Ethylene AlkeneC2H6 Ethane AlkaneC3H4 Propyne AlkyneC3H6 Propene AlkeneC3H8 Propane AlkaneC4H6 1 2 Butadiene DieneC4H6 1 Butyne AlkyneC4H8 1 Butene AlkeneC4H10 Butane AlkaneC6H10 Cyclohexene CycloalkeneC5H12 n pentane AlkaneC7H14 Cycloheptane CycloalkaneC7H14 Methylcyclohexane CyclohexaneC8H8 Cubane Prismane Platonic hydrocarbonC9H20 Nonane AlkaneC10H12 Dicyclopentadiene Diene CycloalkeneC10H16 Phellandrene Terpene Diene CycloalkeneC10H16 a Terpinene Terpene Diene CycloalkeneC10H16 Limonene Terpene Diene CycloalkeneC11H24 Undecane AlkaneC30H50 Squalene Terpene PolyeneC2nH4n Polyethylene AlkaneReferencesIUPAC Compendium of Chemical Terminology 2nd ed the Gold Book 1997 Online corrected version 1995 aliphatic compounds doi 10 1351 goldbook A00217 This organic chemistry article is a stub You can help Wikipedia by expanding it vte
