What characteristic distinguishes esters from other alcohols?

Esters are distinct from other alcohols primarily due to the presence of a specific functional group known as an ester link, which is represented by the structure -COO-. This structure is formed when an alcohol reacts with a carboxylic acid, resulting in the formation of an ester and the elimination of water through a condensation reaction. This ester link is crucial because it defines the chemical behavior and physical properties of esters, differentiating them from alcohols that contain hydroxyl groups (-OH) but lack the ester functional group.

While alcohols contain hydroxyl groups, which contribute to their polarity and hydrogen bonding capabilities, the unique ester link imparts different characteristics, such as pleasant fragrances and varying degrees of solubility in organic solvents. The notion that esters are always solids or highly polar is not accurate, as esters can exist in various physical states and have varying levels of polarity depending on their structure and molecular weight. Thus, the presence of the ester link is what truly sets esters apart from other alcohols.