Alkanols

Alkanols are saturated alcohols which are derived from the alkanes (the saturated hydrocarbons). Note: butane becomes a saturated alcohol, the alkanol becomes butanol. As a functional group, all alkanols have 1 or more hydroxyl group(s). Analogous compounds derived from unsaturated hydrocarbons are called alkenols (with one or more double bonds) and alkynols (with one or more triple bonds).

Valency of alkanols: If the alkanol has a single functional (OH) group, it is called a monohydric alcohol. The general empirical formula of monohydric alkanols is: CnH2n+1OH.

If more than 1 hydroxyl group is present in an alcohol molecule, these are called polyhydric alkanols. An example of a divalent alkanol, an alkanediol, is glycol, the1,2-ethanediol (the number of hydroxyl groups is indicated by the terms "-di-, -tri-, etc. before the suffix -ol"). An example of a trivalent acanol, therefore an alkanetriol, is glycerol (1,2,3-propanetriol). The number before the name of the alkyl radical indicates the position of the functional group(s), in the case of 1,2,3-propanetriol these would be the C atoms numbered 1,2 and 3. This rule also applies to monovalent alkanols, e.g. 2-propanol.

Hydrophilicity/hydrophobicity of alkanols: Hydrophilicity is the most important common characteristic of alkanols. This property of the alkanols increases with the number of hydroxyl groups (the polar hydroxyl group causes the good solubility in water). If the length of the non-polar hydrophobic hydrocarbon chain increases, the solubility in water decreases.

Examples of (monovalent) alkanols (from C1 to C10):

• Methanol (C1 alkanol)
• Ethanol (C2 alkanol)
• 1-Propanol (C3-Alkanol)
• 1-Butanol (C4-Alkanol)
• 1-pentanol (C5 alkanol)
• 1-Hexanol (C6-Alkanol)
• 1-Heptanol (C7-Alkanol)
• 1-octanol (C8 alkanol)
• 1-Nonanol (C9-Alkanol)
• 1-decanol (C10 alkanol)