Deuterated chloroform (CDCl₃), is an isotopologue of chloroform (CHCl₃) in which the hydrogen atom ("H") is replaced with a deuterium (heavy hydrogen) isotope ("D"). Deuterated chloroform is a common solvent used in NMR spectroscopy of organic molecules. In proton NMR spectroscopy, the deuterium does not exhibit a large interfering peak, whereas protium (regular hydrogen) shows a large peak in the spectrum. In carbon-13 NMR, the sole carbon deuterated chloroform shows a triplet at a chemical shift of 77 ppm with the three peaks being about equal size.