OOdiethyl

O,O-diethyl is a chemical descriptor used in organic chemistry to indicate two ethyl groups bound to oxygen atoms within a single molecule. The prefix O,O- (often written with a comma) denotes that two ethoxy or ethyl-oxy substituents are present on two oxygen atoms. It is not a specific compound by itself but a naming convention found in systematic names for diesters and related structures.

In systematic nomenclature, O,O-diethyl is encountered when two ethyl groups are part of ester or ether functionalities in the same molecule. Examples include diethyl esters of dicarboxylic acids and related compounds. For instance, diethyl carbonate and diethyl tartrate are commonly described in literature and recipes with the sense of O,O-diethyl substituents: each ethyl group occupies an oxygen atom in the ester linkage. The descriptor also appears in other diethyl esters such as diethyl adipate, where two ethyl groups are attached through oxygen atoms to a central carbonyl or tartrate backbone.

Because it conveys the presence of two ethyl groups on oxygen, O,O-diethyl is primarily a naming aid rather than a unique chemical identity. The physical properties and hazards depend on the specific core structure (for example, diethyl carbonates versus diethyl tartrates) and follow general organics safety guidelines: many such compounds are flammable liquids and should be handled with typical solvent-care precautions.

See also: ethyl ester, ethoxy group, diester, carbonate esters.