Researches on crystal and molecular structures of nine-coordination mononuclear K[EuIII(Edta)(H2O)3]?3.5H2O and binuclear K4[Eu2III(HTtha)2]?13.5H2O

Abstract

The crystal and molecular structures of the K[EuIII(Edta)(H2O)3] ⋅ 3.5H2O (I) (H4Edta = ethylenediaminetetraacetic acid) and K4[Eu2III(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 [EuIII(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, e = 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 [Eu2III(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.