Synthesis, Crystal Structure And Characterization Of Rare Earth Complexes Based On α-Keggin Type Polyxometalates

In this paper, six new compounds have been synthesized by utilizing the Keggin [H2W)2040]6- clusters as precursors, and rare earth ions or supplemented by organic ligands, through covalen as linkers, by aqueous synthesis methods. And the six compounds are all structurally characterized by IR and single crystal X-ray diffractions.1. By using the lanthanide-pyridine-3,5-dicarboxylic acid coordination complexes as linkers, three three-dimensional structure compounds have been gained based on [H2W12O40]6- polyoxoanions as building blocks.KNa2[Ce2(HL)(L)(H20)9(H2W12040)]·8H20 (1)KNa2[Pr2(HL)(L)(H20)9(H2W12040)]·11H2O (2)KNa2[Sm2(HL)(L)(H2O)9(H2W12O40)]·9H2O (3)H2L= pyridine-3,5-dicarboxylic acidIn compounds 1-3, Ln2 cations coordinate with [H2W12O40]6- polyanions forming a 1D chain structure, and Lnl cations with coordinate with [H2W12O40]6- polyanions forming a 2D snippet. Compounds 1-3 possess 3D extended structures through the covalent of the pyridine-3,5-dicarboxylic acid ligands and lanthanide ions.2. Three two-dimensional structure compounds have been gained, based on [H2W12O40]6-polyoxoanions as building blocks and lanthanide-pyridine-3,5-dicarboxylic acid coordination complexes as linkers:(NH4)3[Gd2(HL)(L)(H20)9(H2W12040)]·7H20 (4)(NH4)3[Tb2(HL)(L)(H20)9(H2W12040)]·9H20 (5)(NH4)3[Dy2(HL)(L)(H2O)9(H2W12O40)]·8H2O (6)H2L= pyridine-3,5-dicarboxylic acidIn compounds 4-6, Ln cations coordinate with [H2W12O40]6- polyanions forming a 1D chain structure,4-6 shows two-dimensional structure by the interaction of Ln cations and pyridine-3,5-dicarboxylic acid ligands.