CH3CH2O

CH3CH2O denotes the ethoxy group, an alkoxy substituent derived from ethanol. It corresponds to the fragment -O-CH2-CH3 and has the formula C2H5O. In chemical contexts the term ethoxy can refer to this substituent when attached to a larger molecule. The same string can also describe related species such as the ethoxide anion (CH3CH2O−) or the ethoxy radical (CH3CH2O•), which differ in charge and reactivity from the neutral moiety.

In organic chemistry, the ethoxy group is commonly encountered in ethers and esters. In ethers, two ethoxy units can connect to form diethyl ether (CH3CH2–O–CH2CH3). In esters, the ethoxy fragment appears as the ethyl ester group -O-CH2CH3, as seen in ethyl acetate (CH3COOCH2CH3). The ethoxy group thus serves as a link between the oxygen atom and an ethyl moiety in a wide range of compounds.

The ethoxide anion, CH3CH2O−, forms when ethanol is deprotonated by a strong base. Ethoxide is a strong base and nucleophile used in organic synthesis for deprotonation steps and SN2 substitutions. It is commonly generated by reacting ethanol with metallic sodium or sodium hydride and is typically handled under anhydrous conditions due to moisture sensitivity.

The ethoxy radical CH3CH2O• is a reactive intermediate in radical chemistry, including combustion and atmospheric processes, as well as in certain radical-promoted reaction mechanisms.

Safety and handling: Ethoxide and ethoxy-containing compounds are caustic and moisture-sensitive; they can react vigorously with water or air and should be handled with appropriate precautions.