Tantalum(III) chloride is formed by reducing tantalum(V) chloride with tantalum metal. this is done by heating tantalum(III) chloride to 305 °C, passing the vapour over tantalum foil at 600°, and condensing the trichloride at 365 °C. If the condensing region is kept at too high a temperature, then TaCl deposits instead.
The trichloride can also be prepared by thermal decomposition of TaCl, with removal of volatile TaCl. TaCl can be vapourised leaving behind TaCl.
"Salt-free reduction" of a toluene solution of TaCl with 1,4-disilyl-cyclohexadiene in the presence of ethylene produces a complex of TaCl: