 Chloroform

Chloroform is trichloromethane, $\mathrm{CHC}{\mathrm{l}}_3$. It is a molecular liquid with three chlorine atoms attached to a tetrahedral carbon center.

Deuterated chloroform, $\mathrm{CDC}{\mathrm{l}}_3$, is widely used as an NMR solvent: replacing most proton signal with deuterium reduces the solvent's proton background and supplies a lock signal. Ordinary chloroform and its deuterated isotopologue therefore have closely related chemistry but different spectroscopic roles.