diacetate

Diacetate is a term used in chemistry to describe a compound that contains two acetate groups derived from acetic acid (CH3COO−). In practice, diacetates most commonly arise as diesters formed when a diol or other multi-oxygen-containing molecule is acetylated, giving compounds such as ethylene glycol diacetate or glycerol diacetate. The term can also refer to diacetate salts, where two acetate groups accompany a metal cation, for example calcium diacetate Ca(CH3COO)2.

Common examples and formats include diacetate esters of diols, where two hydroxyl groups are converted to acetate esters, and diacetate salts in which two acetate ligands balance a divalent metal cation. These compounds may be described by naming patterns such as X, diacetate, where X is the parent diol or amine, or by specifying the metal salt, as in calcium diacetate.

Preparation typically involves acetylation of a diol or polyol with acetylating agents such as acetic anhydride or acetyl chloride under basic or catalytic conditions. Diacetate salts can be prepared by neutralizing acetic acid or acetate sources with the appropriate metal base or by ion exchange.

Applications vary by structure. Diacetate esters are widely used as protecting groups in organic synthesis for hydroxyl-containing substrates. Diacetate salts, notably calcium diacetate, are used as food additives and preservatives because they slowly release acetic acid, contributing antimicrobial properties and flavor.

Properties depend on the specific compound but often include hydrolytic lability (conversion back to acetate and the parent diol or amine) and moderate stability under standard laboratory conditions. Safety follows general ester and acetate handling guidelines.