Preparation and characterization of potassium, rubidium and ammonium tetrachlorouranate(III) trihydrates

The synthesis and characterization of a new series of hydrated uranium(III) complex chlorides of the general formula M¹UCl₄-3H₂O (M¹K, Rb or NH₄) are reported. The compounds crystallize in the monoclinic system. Unit cell parameters were determined from X-ray powder diffraction data. The magnetic susceptibilities of the complex chlorides were measured by the Faraday method in the 4.2–300 K range. The compounds exhibit Curie-Weiss paramagnetism in the 100–300 K range, with the derived effective magnetic moments ranging from 3.57μ_B to 3.71μ_B. Solid state electronic and IR spectra were recorded in the 4000–30 000 and 80–4000 cm⁻¹ ranges, respectively and discussed. Non-static high vacuum thermal dehydrations enabled us to obtain the anhydrous compounds KUCl₄, RbUCl₄ and UCl₃.