Gadolinium(III) and europium(III) L-glutamates: Synthesis and characterization

Abstract

Two lanthanide(III) complexes with L-glutamate ligands [{Ln(2)(L-Glu)(2)(H2O)(8)}center dot 4(ClO4)center dot 2.5H(2)O](n) (Ln = Gd (1), Eu (2)) have been prepared and characterized by single-crystal X-ray diffraction. The compounds are isomorphous with infinite cationic 2D layers stacked together by secondary bonds. The building blocks are slightly different non-centrosymmetric dinuclear units placed in alternating layers, the resulting structures thus containing four non-equivalent Ln metal sites. The dinuclear units contain a fourfold bridge, two in the eta(1):eta(1):mu(2) and two in the eta(2):eta(1):mu(2) modes, from two alpha- and two gamma-carboxylates of four different L-Glu residues, respectively.