Assembly of Lanthanide-Containing Polyoxotantalate Clusters with Efficient Photoluminescence Properties

Abstract

Eight novel lanthanide-containing polyoxotantalates, Cs₃[Ln(H₂O)₆{H₄(TaO₂)₆As₄O₂₄}]·7H₂O (Ln = Sm (<b>1</b>), Eu (<b>2</b>), Tb (<b>3</b>), Dy (<b>4</b>), Er (<b>5</b>), Tm (<b>6</b>), Yb (<b>7</b>), Lu (<b>8</b>)), have been obtained via a one-pot reaction methodology. Each of these compounds is made up of the new type polyanion [(TaO₂)₆As₄O₂₄]^10- with Ln³⁺ linkers, giving a one-dimensional chain. The compounds represent the first family of "pure" Ta-based polyoxometalate lanthanide derivatives. These architectures were characterized by various physicochemical analyses. Furthermore, the photoluminescence properties of compounds <b>2-Eu</b> and <b>8-Lu</b> were also explored, and meanwhile time-resolved emission spectroscopy indicated that the {As₄Ta₆} segment makes a contribution to the energy transfer of compound <b>2</b> from the polyoxotantalate to the Eu^III center, which efficiently facilitates emissions of the Eu³⁺ center.