Investigation on the coordinate structures of the rare earth metal complexes with edta and cydta ligands

The crystal and molecular structures of cydta (trans-1, 2-cyclohexanediaminetetraacetic acid) have been determined by single-crystal X-ray structure analyses. The reasons that REIII-edta and REIII-cydta complexes select different coordinate structures were discussed and illustrated through the comparison of the molecular and crystal structures between edta and cydta, (NH4) [YIII (edta) (H2O)3]·5H2O and (NH4)[YIII (cydta) (H2O)2]·5H2O as well as (NH4) [GdIII (edta) (H2O)3)]·5H2O and (NH4) [GdIII (cydta) (H2O)2]·5H2O complexes.