Spectral and thermal investigations of Y(III) and lanthanide(III) complexes with 3,3-dimethylglutaric acid

Abstract

Conditions of preparation of Y(III) and lanthanide(III) (La-Lu) 3,3-dimetylglutarates were investigated and their quantitative composition and solubility in water at 293 K were determined (10{sup -2} - 10{sup -5} mole dm{sup -3}). The IR spectra of the complexes prepared with the general formula Ln{sub 2}[C{sub 5}H{sub 10}(COO){sub 2}]{sub 3}{center_dot}nH{sub 2}O (n = 2-15) were recorded and their thermal decomposition in air were investigated. During heating the hydrated 3,3-dimethyl glutarates are dehydrated in one (La, Ce, Pr, Sm, Gd, Lu), two (Y, Nd, Eu, Dy, Ho, Tm) or three (Tb, Er) steps and next the anhydrous complexes and dihydrated Yb(III) complex decompose to oxides Ln{sub 2}O{sub 3}, CeO{sub 2}, Pr{sub 6}O{sub 11} and Tb{sub 4}O{sub 7} with intermediate formation Ln{sub 2}O{sub 2}CO{sub 3} except Ce(III) complex, which decomposes directly to CeO{sub 2}. The carboxylate groups in the complexes studied are bidentate. (author)