Polyoxotungstate incorporating organotriphosphonate ligands and lanthanide ions: syntheses, characterization, magnetism and photoluminescence properties.

Four structurally intriguing members of a new family of lanthanide (Ln)-containing organophosphonate-functionalized polyoxotungstates with the general formula K2 [Ln(H2 O)4 (AsW9 O33 )(W2 O3 )(O3 PCOHCH3 PO3 )Ln(H2 O)7 ]2 ·15H2 O [Ln = Ce (1Ce), Nd (2Nd), Sm (3Sm) and Eu (4Eu)] were directly isolated by controlling the reaction parameters and well established by single-crystal X-ray diffraction, PXRD analyses, IR spectra, elemental analyses, TG and EDX analyses. All the four three-dimensional frameworks consist of the S-shaped inorganic building block {[(AsW9 O33 )(W2 O3 )]2 }, two organophosphonate groups {O3 PCOHCH3 PO3 } and four Ln ions. The magnetic properties of the four compounds and the solid-state photoluminescence properties of 2Nd, 3Sm, and 4Eu were also fully investigated.