Deuterated methanol (CD3OD), is a form (called an isotopologue) of methanol (CH3OH) in which the hydrogen atom ('H') is replaced with deuterium (heavy hydrogen) isotope ('D'). Deuterated methanol is a common solvent used in NMR spectroscopy. Deuterated methanol (CD3OD), is a form (called an isotopologue) of methanol (CH3OH) in which the hydrogen atom ('H') is replaced with deuterium (heavy hydrogen) isotope ('D'). Deuterated methanol is a common solvent used in NMR spectroscopy.