Preparation and characterisation of TlLn(SO4)(2)center dot H2O (Ln=Sm to Lu, Y)

The thallium lanthanide double sulphate monohydrates TILn(SO4)(2) . H2O (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 from measurements of peak areas under the differential thermal analysis curve recorded during their thermal dehydration. The X-ray data showed that the crystals are monoclinic, of space group P2(l)lc, with four formula units per unit cell and that the compounds are structurally isomorphous to RbLn(SO4)(2) . H2O reported in the literature. The IR spectra coupled with the X-ray data showed that the trivalent metal ion is coordinated to eight oxygen atoms.