Self-assembly of dilacunary building blocks into high-nuclear [Ln₁₆As₁₆W₁₆₄O₅₇₆(OH)₈(H₂O)₄₂]⁸⁰⁻ (Ln = Eu^III, Gd^III, Tb^III, Dy^III, and Ho^III) polyoxotungstates

A new family of [Ln₁₆As₁₆W₁₆₄O₅₇₆(OH)₈(H₂O)₄₂]⁸⁰⁻ (Ln = Eu^III, Gd^III, Tb^III, Dy^III, and Ho^III) nanoclusters has been synthesized from a self-assembly process in solution. The novel macroanion is constituted of two identical sub-units with the formula [Gd₈As₈W₈₂O₂₈₈(OH)₄(H₂O)₂₁]⁴⁰⁻ and it was obtained from the versatile building block [As₂W₁₉O₆₇(H₂O)]¹⁴⁻ in combination with mid to late lanthanoid cations. All compounds have been structurally characterized and the magnetic properties of the Gd-containing member of the series have been investigated. The novel macroanion represents the largest polyoxotungstate reported to date and the influence of the templating cations on the molecular architecture is discussed. Furthermore, the spectrum of lanthanide linkers for the construction of large polyoxotungstates has been amplified in the present approach.