Three-dimensional lanthanide polyoxometalate organic complexes: correlation of structure with properties

Abstract

A family of three-dimensional (3D) architectures based on lanthanide-substituted polyoxotungstate building blocks [Ln(HL)(L)(H₂O)₆{Ln(H₂L)_0.5(α-PW₁₁O₃₉H)Ln(H₂O)₄}]₂·nH₂O (Ln = La, n = 8 (1); Ln = Ce, n = 12 (2); Ln = Pr, n = 8 (3); H₂L = 2,5-pyridinedicarboxylic acid) have been successfully synthesized under hydrothermal conditions and further characterized by elemental analyses, X-ray powder diffraction (XRPD), IR spectra, UV spectra, thermogravimetric (TG) analyses and single-crystal X-ray diffraction. The common features of 1–3 are that they all consist of 1D zigzag chain [{Ln(α-PW₁₁O₃₉H)}₂]⁶⁻ moieties and the chains further form into 3D structure via metal–organic cations. Furthermore, the photocatalysis properties of 1–3 for degradation of the rhodamine-B (RhB) upon 500 W Hg lamp irradiation have been examined. The magnetic properties of compounds 2 and 3 have been studied by measuring their magnetic susceptibility in the temperature range of 2–300 K.