Structural and spectroscopic investigations of the Eu-III-CDTA system

摘要

Two crystal structures of Eu-III complexes with CDTA (trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetate), [C(NH2)(3)](3)[Eu-2(CDTA)(2)(H2O)(2)]ClO4 center dot center dot 7H(2)O (I) and [C(NH2)(3)][Eu(CDTA)(H2O)] center dot 2.375H(2)O (II), are presented. Both structures are polymeric and the central metal ions are eight-coordinate. The first coordination sphere of each Eu-III cation contains five carboxylate oxygen atoms, two nitrogen ones and a water molecule. For I, as well as for water solutions of the Eu-III-CDTA complex at various pH values, the spectroscopic (UV-Vis) properties were investigated. (c) 2006 Elsevier Ltd. All rights reserved.