Assembly of three novel 2D frameworks with helical chains based on [H2W12O40]6− clusters and lanthanide – Organic complexes

Three novel polyoxotungstate-based rare earth compounds, [(C6H5NO2)Ln(H2O)5]2[H2W12O40] · nH2O (Ln = Ce3+ (1), Pr3+(2), n = 7; Nd3+ (3), n = 6), have been synthesized in aqueous solution and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectra and TG analysis. The structural feature of compounds 1–3 is that the α-metatungstate cluster [H2W12O40]6− anions are linked by the lanthanide (Ln) cation–organic coordination complexes, resulting in a two-dimensional (2D) structure with helical chains. The magnetic properties of compounds 1 and 2 have been studied by measuring their magnetic susceptibility in the temperature range 2–300 K, indicating the existence of spin–orbital coupling interactions and antiferromagnetic response. Furthermore, the electrochemical properties of 1–3 were studied.