What suffix is used for diols in chemical nomenclature?

Diols are organic compounds that contain two hydroxyl (-OH) groups. In chemical nomenclature, the suffix used to indicate the presence of these two hydroxyl groups on a hydrocarbon chain is specifically “-diol.” This suffix helps to differentiate diols from alcohols that contain only one hydroxyl group, which are designated with the suffix “-ol.”

For example, in the case of ethylene glycol, the compound has two hydroxyl groups attached to a two-carbon alkane, and is named ethane-1,2-diol. The “-diol” suffix clearly indicates that there are two alcohol functional groups present, which is key to understanding the structure and reactivity of these compounds in organic chemistry.

The other suffixes do not fit the context of diols. “-ane” is used for alkanes (saturated hydrocarbons with single bonds), “-onate” typically refers to esters or salts of carboxylic acids, and “-ol” is used solely for monohydric alcohols. Hence, the use of “-diol” in nomenclature accurately conveys the presence of two hydroxyl groups in the structure of the compound.