Trichloride may refer to: The trichloride ion, a polyhalogen ion Antimony trichloride, SbCl3 also known as butter of antimony Arsenic trichloride, AsCl3, also known as arsenous chloride or butter of arsenic Boron trichloride, BCl3, a colorless gas and valuable reagent in organic synthesis Butyltin trichloride, an organotin compound Gallium trichloride, GaCl3 Iodine trichloride, ICl3 Nitrogen trichloride, NCl3, a yellow, oily, pungent-smelling liquid is most commonly encountered as a byproduct of reactions between ammonia-derivatives and chlorine Phosphorus trichloride, PCl3, a yellow solid Rhenium trichloride, ReCl3