Syntheses and structural determinations of the nine-coordinate rare earth metal: Na4[DyIII(dtpa)(H2O)]2·16H2O, Na[DyIII(edta)(H2O)3]·3.25H2O and Na3[DyIII(nta)2(H2O)]·5.5H2O

Abstract

Three complexes, Na4[DyIII(dtpa)(H2O)]2 · 16H2O, Na[DyIII(edta)(H2O)3] · 3.25H2O and Na3[DyIII (nta)2(H2O)] · 5.5H2O, have been synthesized in aqueous solution and characterized by FT–IR, elemental analyses, TG–DTA and single-crystal X-ray diffraction. Na4[DyIII(dtpa)(H2O)]2 · 16H2O crystallizes in the monoclinic system with P21/n space group, a = 18.158(10) Å, b = 14.968(9) Å, c = 20.769(12) Å, β = 108.552(9)°, V = 5351(5) Å3, Z = 4, M = 1517.87 g mol−1, D c = 1.879 g cm−3, μ = 2.914 mm−1, F(000) = 3032, and its structure is refined to R 1(F) = 0.0500 for 9384 observed reflections [I > 2σ(I)]. Na[DyIII(edta)(H2O)3] · 3.25H2O crystallizes in the orthorhombic system with Fdd2 space group, a = 19.338(7) Å, b = 35.378(13) Å, c = 12.137(5) Å, β = 90°, V = 8303(5) Å3, Z = 16, M = 586.31 g mol−1, D c = 1.876 g cm−3, μ = 3.690 mm−1, F(000) = 4632, and its structure is refined to R 1(F) = 0.0307 for 4027 observed reflections [I > 2σ(I)]. Na3[DyIII(nta)2(H2O)] · 5.5H2O crystallizes in the orthorhombic system with Pccn space group, a = 15.964(12) Å, b = 19.665(15) Å, c = 14.552(11) Å, β = 90°, V = 4568(6) Å3, Z = 8, M = 724.81 g mol−1, D c = 2.102 g cm−3, μ = 3.422 mm−1, F(000) = 2848, and its structure is refined to R 1(F) = 0.0449 for 4033 observed reflections [I > 2 σ(I)]. The coordination polyhedra are tricapped trigonal prism for Na4[DyIII(dtpa)(H2O)]2 · 16H2O and Na3[DyIII(nta)2(H2O)] · 5.5H2O, but monocapped square antiprism for Na[DyIII(edta)(H2O)3] · 3.25H2O. The crystal structures of these three complexes are completely different from one another. The three-dimensional geometries of three polymers are 3-D layer-shaped structure for Na4[DyIII(dtpa)(H2O)]2 · 16H2O, 1-D zigzag type structure for Na[DyIII(edta)(H2O)3] · 3.25H2O and a 2-D parallelogram for Na3[DyIII(nta)2(H2O)] · 5.5H2O. According to thermal analyses, the collapsing temperatures are 356°C for Na4[DyIII(dtpa)(H2O)]2 · 16H2O, 371°C for Na[DyIII(edta)(H2O)3] · 3.25H2O and 387°C for Na3[DyIII(nta)2(H2O)] · 5.5H2O, which indicates that their crystal structures are very stable.