PREPARATION AND CHARACTERIZATION OF TLLN(SO4)(2)CENTER-DOT-H2O (LN=SMTO LU, Y)

The thallium lanthanide double sulphate monohydrates TILn(SO4)(2) . H2 O (Ln = Sm to Lu and Y) were synthesized and characterised by chemical , thermal, infrared and X-ray powder diffraction methods. The heats of dehydration of all the TILn(SO4)(2) . H2O compounds were calculated f rom measurements of peak areas under the differential thermal analysis curve recorded during their thermal dehydration. The X-ray data showe d that the crystals are monoclinic, of space group P2(l)lc, with four formula units per unit cell and that the compounds are structurally is omorphous to RbLn(SO4)(2) . H2O reported in the literature. The IR spe ctra coupled with the X-ray data showed that the trivalent metal ion i s coordinated to eight oxygen atoms.