Chloroaluminate Ionic Liquids as Reagents for Isolating Soluble Hexanuclear Zirconium Halide Cluster Compounds

Ambient-temperature chloroaluminate molten salts, mixtures of aluminum trichloride (AlCl3) and 1-ethyl-3-methylimidazolium chloride (ImCl), have been used as solvents to excise and isolate centered hexanuclear zirconium halide clusters from their solid-state precursors. Cluster compounds synthesized via high-temperature reactions, KZr6CCl15 and Li2Zr6MnCl15, were dissolved into basic molten salts at 100−110 °C. The C-centered cluster compound, Im4Zr6CCl18, was isolated in 70% yield, and the Mn-centered cluster compound, Im5Zr6MnCl18·C7H8·2CH3CN, was isolated in 54% yield. Im5Zr6BCl18 is efficiently oxidized by ferrocenium tetrafluoroborate, and one-electron-oxidized B-centered cluster, [(Zr6B)Cl18]4-, was isolated in 90% yield as the salt Im4Zr6BCl18.