Deuterated ethanol (C<sub>2</sub>D<sub>5</sub>OD or CD<sub>3</sub>CD<sub>2</sub>OD) is a form (called an isotopologue) of ethanol (C<sub>2</sub>H<sub>5</sub>OH) in which the hydrogen atom ("H") is replaced with deuterium (heavy hydrogen) isotope ("D"). Deuterated ethanol is an uncommon solvent used in NMR spectroscopy.