Hydrothermal Synthesis and Crystal Structure of One Rare Earth Substituted Keggin-Type Germanotungstate [Cu(en)2]2[Cu(en)2(H2O)]2H3{[Cu(en)2]2[Na2(H2O)1.75][K(H2O)3][Dy2(H2O)2 (GeW11O39)3]} · 6H2O

A novel germanotungstate derivative based on the dysprosium cation and monovacant Keggin anion, [Cu(en)2]2[Cu(en)2(H2O)]2H3{[Cu(en)2]2[Na2(H2O)1.75][K(H2O)3][Dy2(H2O)2(GeW11O39)3]} · 6H2O(en = ethylenediamine) 1, has been synthesized by hydrothermal method and characterized by elemental analysis, IR-UV spectroscopy, thermal analysis and single-crystal X-ray diffraction. In the compound, one kind of clusters with the Dy3+/[GeW11O39]8− ratio of 2:3 was observed. Especially, the 2:3 type displays the novel cluster based on the rare earth and monolacunary Keggin polyoxometalate.