Chloroform-D (Cas number: 865-49-6) is a deuterated compound and a member of chloromethanes. 

This deuterium compound is invisible in the NMR spectrometer which means interfering signals from the protons present in the solvent are avoided. Many modern spectrometers use the trace undeuterated solvent as an internal parameter for determining relative chemical shifts.

Deuterated compounds have many applications for advanced academic research and some other applications such as tracking the progress of complex chemical reactions and optimizing the properties of drugs