Assembly of three novel 2D frameworks with helical chains based on [H 2W 12O 40] 6− clusters and lanthanide – Organic complexes

Abstract

Three novel polyoxotungstate-based rare earth compounds, [(C 6H 5NO 2)Ln(H 2O) 5] 2[H 2W 12O 40] · nH 2O (Ln = Ce 3+ ( 1), Pr 3+( 2), n = 7; Nd 3+ ( 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 [H 2W 12O 40] 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.