Syntheses and structures of nine-coordinate K3[DyIII(nta)2(H2O)]·5H2O and eight-coordinate (NH4)3[DyIII(nta)2] complexes

K3[DyIII(nta)2(H2O)]·5H2O and (NH4)3[DyIII(nta)2] have been synthesized in aqueous solution and characterized by IR, elemental analysis and single-crystal X-ray diffraction techniques. In K3[DyIII(nta)2(H2O)]·5H2O the DyIII ion is nine coordinated yielding a tricapped trigonal prismatic conformation, and its crystal belongs to monoclinic system and C2/c space group. The crystal data are as follows: a = 15.373(5) Å, b = 12.896(4) Å, c = 26.202(9) Å; β = 96.122(5)°, V = 5165(3) Å3, Z = 8, Dc = 1.965 g·cm−3, μ = 3.458 mm−1, F(000) = 3016, R1 = 0.0452 and wR2 = 0.1025 for 4550 observed reflections with I ≥ 2σ(I). In (NH4)3[DyIII(nta)2] the DyIII ion is eight coordinated yielding a usual dicapped trigonal anti-prismatic conformation, and its crystal belongs to monoclinic system and C2/c space group. The crystal data are as follows: a = 13.736(3) Å, b = 7.9389(16) Å, c = 18.781(4) Å; β = 104.099(3)°, V = 1986.3(7) Å3, Z = 2, Dc = 1.983 g·cm−3, μ = 3.834 mm−1, F(000) = 1172, R1 = 0.0208 and wR2 = 0.0500 for 2022 observed reflections with I ≥ 2σ(I). The results indicate that the difference in counter ion also influences coordination numbers and structures of rare earth metal complexes with aminopolycarboxylic acid ligands.