Ln12-containing 60-tungstogermanates: synthesis, structure, luminescence, and magnetic studies

Abstract

A new class of hexameric Ln12-containing 60-tungstogermanates, [Na(H2O)6⊂Eu12(OH)12(H2O)18Ge2(GeW10O38)6]39− (Eu12), [Na(H2O)6⊂Gd12(OH)6(H2O)24Ge(GeW10O38)6]37− (Gd12), and [(H2O)6⊂Dy12(H2O)24(GeW10O38)6]36− (Dy12), comprising six di-Ln-embedded {β(4,11)-GeW10} subunits was prepared by reaction of [α-GeW9O34]10− with LnIII ions in weakly acidic (pH 5) aqueous medium. Depending on the size of the LnIII ion, the assemblies feature selective capture of two (for Eu12), one (for Gd12), or zero (for Dy12) extra GeIV ions. The selective encapsulation of a cationic sodium hexaaqua complex [Na(H2O)6]+ was observed for Eu12 and Gd12, whereas Dy12 incorporates a neutral, distorted-octahedral (H2O)6 cluster. The three compounds were characterized by single-crystal XRD, ESI-MS, photoluminescence, and magnetic studies. Dy12 was shown to be a single-molecule magnet.