Compounds based on cluster anion [Re4Te4(CN)12]4−, Ln3+ cations (Ln = Gd, Tb, Dy, Ho, Er) and 4,4′-bipyridine: Synthesis, structure and properties

Compounds with general formula (bipyH2)[{Ln(H2O)6}{Re4Te4(CN)12}]2·10H2O (Ln = Gd (1), Dy (2), Tb (3), Ho (4), Er (5)) were obtained by evaporation of acidic aqueous solution containing salts of [Re4Te4(CN)12]4− cluster anion, respective lanthanide cation and 4,4′-bipyridine. Structures of compounds 1–5 consist of dimeric cluster fragments [{Ln(H2O)6}{Re4Te4(CN)12}]22−, forming supramolecular ionic structure with outer-sphere 4,4′-bipyridinium cations and H2O molecules. Magnetic susceptibility of all compounds in the range of temperature 80–300 K was measured; thermal stability was also investigated.