Synthesis and structures of nine-coordinate K[SmIII (Edta)(H2O)3] · 2H2O and Ten-Coordinate K2[SmIII(Pdta)(H2O)2]2 · 4.5H2O complexes

Abstract

The title complexes, K[SmIII(Edta)(H2O)3] · 2H2O(I)(H4Edta = ethylenediamine-N,N,N′,N′-tetraacetic acid) and K2[SmIII(Pdta)(H2O)2]2 · 4.5H2O (II) (H4Pdta = propylenediamine-N,N,N′,N′-tetraacetic acid), were prepared and their compositions and structures were determined by elemental analyses and single-crystal X-ray diffraction techniques, respectively. Complex I has a mononuclear structure, and the Sm3+ ion is nine-coordinated by an Edta ligand and three water molecules, yielding a pseudo-monocapped square antiprismatic conformation, and the complex crystallizes in the orthorhombic crystal system with space group Fdd2. The crystal data are as follows: a = 19.84(5), b = 35.58(9), c = 12.15(3) A, V = 8580(38) A3, Z = 16, ρc = 1.925 g/cm3, μ = 3.010 mm−1, F(000) = 4976, R = 0.0252, and wR = 0.0560 for 3510 observed reflections with I ≥ 2σ(I). Complex II has a binuclear structure and the Sm3+ ion is ten-coordinated by a Pdta ligand, two oxygen atoms from a carboxylic group of adjacent Pdta ligand and two water molecules, yielding a distorted bicapped square antiprismatic prism. The complex crystallizes in the triclinic crystal system with space group P\( \bar 1 \). The crystal data are as follows: a = 8.9523(15), b = 10.7106(15), c = 11.6900(19) A, α = 80.613(5)°, β = 80.397(5)°, γ = 76.530(4)°, V = 1065.7(3) A3, Z = 1, ρc = 1.970 g/cm3, μ = 2.532 mm−1, F(000) = 1620, R = 0.0332 and wR = 0.0924 for 5390 observed reflections with I ≥ 2σ(I).