Syntheses and structural determination of eight-coordinate Na[Yb^III(Cydta)(H₂O)₂] · 5H₂O and [Yb^III(Hegta)] · 2H₂O complexes

Abstract

Na[Yb^III(Cydta)(H₂O)₂] · 5H₂O (1) (H₄Cydta = trans-1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid) and [Yb^III(Hegta)] · 2H₂O (2) (H₄egta = ethyleneglycol-bis-(2-aminoethylether)-N,N,N′,N′-tetraacetic acid) were prepared and their composition and structures were determined by elemental analyses and single-crystal X-ray diffraction techniques. Complex 1 crystallized in the triclinic crystal system with space group P 1; the Yb^III is eight-coordinate by a hexadentate Cydta and two water molecules. Complex 2 is a protonated egta complex, crystallized in the monoclinic crystal system with space group P 2 ₁ /c; Yb^III is coordinated only by the octadentate Hegta ligand. Both these complexes adopt a pseudo-square antiprismatic conformation.

Keywords:

• Yb^III ion
• Trans-1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid (H₄Cydta)
• Ethyleneglycol-bis (2-aminoethylether)-N,N,N′,N′-tetraacetic acid (H₄egta)
• Eight-coordination

Acknowledgements

We thank Professors K. Miyoshi and T. Mizuta (Faculty of Science, Hiroshima University, Japan) for instruction and Dr N.H. Hu (Changchun Institute of Applied Chemistry, Chinese Academy of Science) for the single crystal X-ray structural determination. We also thank our colleagues and other students for their participation in this work. These projects were supported by the National Natural Science Foundation of China, Liaoning Province Natural Science Foundation of Education Department and Liaoning Province Natural Science Foundation of Science and Technology Department.