The Study Of The Derivatives Based On Keggin-type Polyoxometalates (Ⅲ)

The aim of this thesis is the synthesis of six novel inorganic-organic hybrid compounds based on Keggin-type polyoxometalates cluster and bis(undecatungstogermanate) lanthanates clusters, which are bridged by the oxalate-bridged dinuclear copper metalorganic complex under open-air mild reaction condition. These inorganic-organic hybrid compounds are characterized by elemental analysis, IR spectrum, thermal stability analysis, single-crystal X-ray diffraction and magnetic properties of some of compounds have also studied and discussed.1. An novel inorganic-organic hybrid based on Keggin-type polytungstate linked dinuclear copper (II)–oxalate complex has been synthesized and characterized in acidic aqueous solutions: H2[Cu2(bpy)2(H2O)2(μ-ox)]2[H2W12O40]·9H2O (bpy = 2,2'-bipyridine,ox= C2O42-) (1)Magnetic susceptibility studies reveal that the compound 1 shows antiferromagnetic coupling between the neighboring Cu2+ ions in the structure, and the compound 1 also displays a good catalytic activity with the conversion 42.4% for H2O2 decomposition.2. Five hybrid compounds have been synthesized based on bis(undecatungstogermanate) lanthanates as the building block and dinuclear copper(II)–oxalate complexes serve as the bridging group: K2Na4H5[{La(GeW11O39)2}{Cu2(bpy)2(μ-ox)}]·19H2O (2) K2Na4H5[{Nd(GeW11O39)2}{Cu2(bpy)2(μ-ox)}]·17H2O (3) K2Na4H5[{Sm(GeW11O39)2}{Cu2(bpy)2(μ-ox)}]·22H2O (4) K2Na9[{Eu(GeW11O39)2}{Cu2(bpy)2(μ-ox)}]·20H2O (5) K2Na2H7[{Gd(GeW11O39)2}{Cu2(bpy)2(μ-ox)}]·19H2O (6)Compound 2-6 are isomorphic, consisting of 1D chain structure. The 1D chain further connects into 3D framework byπ–πinteractions of bpy groups from neighboring chains. The magnetic susceptibility data of 2, 3 and 6 indicate that there dominating exist antiferromagnetic coupling between the dinuclear copper, and rare earth ions play a role in magnetic property in the structure for 3 and 6.