Syntheses and Structural Studies of Nine-Coordinate Mononuclear KEu~Ⅲ(edta)(H_2O)_3·3.5H_2O and Binuclear K_4Eu~~Ⅲ__2(Httha)_2·13.5H_2O Complexes

摘要

The crystal and molecular structures of K[EuⅢ（edta）（H2O）3]·3.5H2O （H4 edta=ethylenediaminetetraacetic acid） and K4[EuⅢ2（Httha）2]·13.5H2O （H6 ttha=triethylenetetraminehexaacetic acid） complexes were determined by single-crystal X-ray structure analyses. The crystal of K[EuⅢ（edta）（H2O）3]·3.5H2O complex 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, Dc=1.835 g·cm-3, μ=3.166 mm-1 and F（000）=4752. The final R and wR values are 0.0269 and 0.0692 for 2936 [I>2.0σ（I）] reflections, and 0.0317 and 0.0708 for all 7284 unique reflections, respectively. The [EuⅢ（edta）（H2O）3]-complex anion has a nine-coordinate pseudo-monocapped square antiprismatic structure in which the nine coordinate atoms, two N and seven O are from one edta ligand and three water molecules. The crystal of the K4[EuⅢ2（Httha）2]·13.5H2O complex belongs to monoclinic system and P2（1）/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, Dc=1.773 g·cm-3, μ=2.339 mm-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 26048 unique reflections, respectively. The complex molecule is composed of two close parts in structure. Every part around the EuⅢ ion in the [EuⅢ2（Httha）2]4- complex anion has a nine-coordinate structure with distorted monocapped square antiprismatic prism, in which the ttha ligand coordinates to one central EuⅢ ion with three N atoms and four O atoms and to the other EuⅢ ion with two O atoms.