C5H11OH

C5H11OH is the molecular formula used for pentanol, the family of five-carbon alcohols that contain a hydroxyl group. When written as C5H12O, it represents the same set of compounds; C5H11OH emphasizes the alcohol functional group.

There are eight constitutional isomers of pentanol, differing in carbon skeleton and the position of the hydroxyl group. The eight are: pentan-1-ol (1-pentanol); pentan-2-ol (2-pentanol); pentan-3-ol (3-pentanol); 2-methylbutan-1-ol; 3-methylbutan-1-ol; 2,2-dimethylpropan-1-ol; 2-methylbutan-2-ol; and 3-methylbutan-2-ol. The straight-chain isomers include the three pentanols, while the branched isomers account for the other five. Of these, 2-pentanol is a chiral secondary alcohol and exists as enantiomeric pairs; the others are typically achiral.

Physical properties vary with structure. In general, pentanols are colorless liquids or low-boiling liquids that are miscible with many organic solvents. Boiling points tend to be higher for linear isomers and decrease with increased branching. As with other alcohols, the hydroxyl group drives hydrogen bonding, contributing to relatively higher boiling points than nonpolar hydrocarbons of similar mass.

Applications and occurrence: pentanol isomers are used as solvents, intermediates in organic synthesis, and aroma or flavor components in some contexts. They also appear in trace amounts in fermentation products known as fusel oils.

Safety: pentanols are typically flammable and can be irritating to skin and eyes. They should be handled with appropriate precautions in well-ventilated areas away from heat sources.