Rubidium-templated bowl-shaped isopolyoxoantimonates [RbH₁₁˗ₓ(RSb)₁₄O₃₄]ₓ˗ derived from arylstibonic acids

Abstract

Arylstibonic acids, RSbO₃H₂ (R = p-MeC₆H₄- or p-ClC₆H₄-) when neutralised in the presence of Rb⁺ give isopolyoxometalates derived from [RbH₁₁(RSb) ₁₄O₃₄]. The X-ray crystal structures of four examples were determined and all gave the same basic framework with a bowl-shaped Sb14 polyhedron cradling the Rb⁺ in an 11-coordinate embrace. All were further linked into chains in the lattice by an intermolecular interaction involving a second Rb⁺, coordinated to three O atoms of one polyoxometalate and to an aryl group of an adjacent unit via an η⁶ interaction. One example has the same basic structure but with one framework O atom replaced by a Br.