A fully reduced {VIV18O42} host and VO43−, Cl− as guest anions: synthesis, characterization and proton conductivity

Two polyoxovanadate compounds, [Na₇(H₂O)₁₄][H₈VIV18O₄₂(V^VO₄)]·N₂H₄·7H₂O and [Na₅(H₂O)₁₆][H₈VIV18O₄₂(Cl)]·4N₂H₄·6H₂O, each having fully reduced host cage and accommodating eight acidic protons per formula unit, exhibit moderate proton conductivity.