XAFS Study of the Local Structure of Some Lanthanoid(III) Complexes

Two types of lanthanoid(III) complexes were synthesized: type I complexes - Ln(III) (Ln = Sm, Eu, Tb, Dy) anthrarufinate complexes using anthrarufin (1,5-dihydroxy-9,10-anthraquinone) as the ligands, and type II complexes - Ln(III)-transition(d-bloch) metal(II) bi-nuclear complexes. The local structures of these complexes were studied by EXAFS spectroscopy. We found that there is a good linear correlation between the ionic radii of Ln(III) and the Ln-O distances for the type I complexes, and for type II complexes the interatomic distances between Gd and coordinated oxygen atoms of the bi-nuclear complex are shorter than those of the Gd mononuclear complex