SYNTHESIS AND CHARACTERIZATION OF CESIUM TETRACHLOROURANATE(III) AND DICESIUM LITHIUM HEXACHLOROURANATE(III)

Uranium(III) chloro complexes of formulae CsUCl4 and Cs2LiUCl6 were sy nthesized and characterized by electronic absorption, X-ray powder dif fraction and magnetic susceptibility investigation. Cs2LiUCl6 crystall izes in the regular system Fm3m, with a = 10.671 Angstrom, V = 1218.03 Angstrom(3) and Z = 4. The powder diffraction data for CsUCl6 could n ot be indexed unambiguously. The following paramagnetic constants were obtained: C = 1.215 emu K mol(-1), Theta = -32.7 K, mu(eff) = 3.13 B. M. (for CsUCl4) and C = 1.571 emu K mol(-1), Theta = -103 K, mu(eff) = 3.56 B.M. (for Cs2LiUCl6). Solid state electronic spectra of the comp ounds were recorded in the range 4000-30 000 cm(-1) and are discussed. An analysis of the 5f(3) --> 5f(2)6d(1) transitions in the absorption spectrum of Cs2LiUCl6 is presented. (C) 1998 Published by Elsevier Sc ience S.A.