Structural characterization of two lanthanide compounds based on polyoxometalate building units

Two new compounds [Hbpy]2[Ce(Hbpy)(DMF)5(H2O)2][H2W12O40] · 0.5H2O (1) and [La(DMF)7(H2O)][PMo12O40] · DMF · (CH3)2NH (2) (DMF = N,N-dimethylformamide, bpy=4,4′-bipyridine) have been synthesized and characterized by single-crystal X-ray diffraction, IR spectra, TG analysis and electrochemical analysis. In 1, the [Ce(Hbpy)(DMF)5(H2O)2]4+ unit is supported on the α-Keggin polyoxoanion [H2W12O40]6− via bridging oxygen atoms, and further extended into 2-D supramolecular networks by hydrogen-bonding and π–π interactions. There exist one-dimensional channels surrounded by supramolecular interactions, in which 4,4′-bipy ligands reside. Compounds constructed from Ln(III) and [H2W12O40]6− polyoxoanions are rare. For 2, the [La(DMF)7(H2O)]3+ is supported by [PMo12O40]3− units via the surface bridging oxygens, and further extended into 2-D supramolecular networks through hydrogen bonds. As for 1, a one-dimensional channel exists in 2, in which DMF resides. To our surprise, (CH3)2NH molecules exist in the structure o...