Researches on crystal and molecular structures of nine-coordination mononuclear K[Eu^III(Edta)(H₂O)₃]⋅3.5H₂O and binuclear K₄[Eu ^III₂ (HTtha)₂]⋅13.5H₂O

Abstract

The crystal and molecular structures of the K[Eu^III(Edta)(H₂O)₃] ⋅ 3.5H₂O (I) (H₄Edta = ethylenediaminetetraacetic acid) and K₄[Eu ^III₂ (HTtha)₂] ⋅ 13.5H₂O (II) (H₆Ttha = triethylenetetraminehexaacetic acid) complexes have been determined by single-crystal X-ray diffraction analyses. The crystal of I belongs to orthorhombic crystal system and Fdd2 space group. The crystal data are as follows: a = 1.9849(6)nm, b = 3.5598(11)nm, c = 1.2222(4)nm, V = 8.636(5)nm³, Z = 16, M = 596.37, ρ(calcd) = 1.835g/cm³, µ= 3.166mm⁻¹, and F (000) = 4752. The final R and wR values are 0.0269 and 0.0692 for 2936 (I > 2.0 σ(I)) reflections and 0.0317 and 0.0708 for all 7284 unique reflections, respectively. The [Eu^III(Edta)(H₂O)₃]⁻ complex anion has a nine-coordination pseudo-monocapped square antiprismatic structure in which the nine coordinated atom are two N and seven O atoms (four from one Edta ligand and three water molecules). The crystal of II belongs to monoclinic system and P2¹/n space group. The crystal data are as follows: a = 1.1337(3)nm, b = 2.5753(6)nm, c = 2.2138(6) nm, β= 102.871(5)°, V = 6.301(3) nm³, Z = 4, M = 1682.33, ρ(calcd) = 1.773g/cm³, ε = 2.339mm⁻¹, and F(000) = 3404. The final R and wR are 0.0514 and 0.0906 for 11144 (I> 2.0σ(I)) reflections and 0.0976 and 0.1068 for all 26 048 unique reflections, respectively. The whole complex molecule is composed of two close parts in which every one has a nine-coordination structure as a distorted monocapped square antiprism. The Ttha ligand in the [Eu ^III₂ (HTtha)₂]⁴⁻ complex anion coordinates to one central Eu ³⁺ ion with three N atoms and four O atoms and to the other Eu³⁺ ion with two O atoms.