Thorium(IV) chloride describes a family of inorganic compounds with the formula ThCl4(H2O)n. Both the anhydrous and tetrahydrate (n = 4) forms are known.

[1] ThCl4 was an intermediate in the original isolation of thorium metal by Jons Jacob Berzelius.

[2] Thorium(IV) chloride can be produced in a variety of ways.

One method is a carbothermic reaction, 700 °C to 2600 °C, involving thorium oxides and carbon in a stream of chlorine gas: The chlorination reaction can be effected with carbon tetrachloride:[3][4] In another two-step method, thorium metal reacts with ammonium chloride: The hexachloride salt is then heated at 350 °C under a high vacuum to produce ThCl4.

[5] ThCl4 reacts with Lewis bases to give molecular adducts, such as ThCl4(DME)2 and ThCl4(TMEDA)2.