Magnetic, thermal and spectroscopic properties of lanthanide(III) 2-(4-chlorophenoxy) acetates, Ln(C8H6ClO3)3•nH2O

Abstract

4-Chlorophenoxyacetates of lanthanides(III) were synthesized as polycrystalline hydrated solids with the general formulae: Ln(C8H6ClO3)3?2H2O (Ln = La(III), Pr(III), Sm(III), Eu(III) and Tb(III)), Ln(C8H6ClO3)3?H2O (Ln = Dy(III)) and Ln(C8H6ClO3)3?3H2O (Ln = Er(III), Tm(III), Yb(III) and Lu(III) and characterized by elemental analysis, FTIR spectroscopy, magnetic and thermogravimetric studies and also by X-ray diffraction (XRD) measurements. The complexes have colours typical for lanthanide(III) ions. The carboxylate groups bind as bidentate chelating. On heating to 1273 K in air the complexes decompose in three steps. At first they dehydrate in one stage to form anhydrous salts that next decompose to the oxides of respective metals with the intermediate formation of their oxychlorides. The gaseous products of compound thermal decomposition in nitrogen were also determined and the magnetic susceptibilities were measured over the ranges 76-303K and 1.8-303K, and their magnetic moments were calculated. The results show that 4-chlorophenoxyacetates of lanthanides(III) are high-spin complexes with weak ligand field.