Thallic fluochloride, TlFCl₂

Thallic fluochloride, TlFCl₂.3H₂O, is obtained in white needles by the action of chlorine on thallous fluoride dissolved in aqueous hydrofluoric acid. It becomes anhydrous when kept over phosphoric anhydride, and the anhydrous salt forms a double salt with potassium chloride, of the formula 2TlFCl₂.KCl, and a compound with ammonia, of the formula TlFCl₂.4NH₃. Analogous compounds of the composition TlFBr₂ and TlFBr₂.4NH₃ are also known.