Spectral and thermal studies of yttrium and heavy lanthanide 2,6-dihydroxybenzoates

The complexes of Y(III) and heavy lanthanides(III) (Gd-Lu) with 2,6-dihydro xybenzoic acid have been prepared and their IR spectra, solubilities in wat er and thermal decomposition have been investigated. The complexes [Ln(C7H5 O4)(3)(H2O)(4)] . 2H(2)O, when heated, lose their crystallization water in two steps and then decompose to the oxides Ln(2)O(3) and Tb4O7 with interme diate formation of Ln(C7H5O4)(C7H4O4) In the complexes prepared, the carbox ylate groups act as monodentate and bidentate chelating ligands. The water molecules are linked in inner and outer spheres. The complexes of Y(III) an d heavy lanthanides (Gd-Lu) are isostructural.