Preparation and crystal structure of new samarium complexes with glutamic acid

Samarium complexes with glutamic acid containing cationic [Sm-2(Glu)(2)(H2O)(8)](4+) units have been prepared and characterized by using elemental analysis, infrared absorption spectra and thermal analysis. In addition, the crystal and molecular structure of [Sm-2(Glu)(2)(H2O)(8)](ClO4)(4)(.)3H(2)O was determined by X-ray diffraction. The presence of glutamic acid in the Sm coordination sphere allows the formation of a singular extended 2D arrangement. Sm atoms are nine coordinated, in a monocapped square antiprism geometry. They are connected by means of different mu-COO- bridges, involving alpha- and gamma-carboxylate groups of the amino acid. (C) 2003 Elsevier B.V. All rights reserved.