A novel one-dimensional chain-like structure based on sandwich-type tungstoantimonate and cadmium(II)

A novel cadmium-substituted tungstoantimonate [Sb₂W₂₁Cd(OH)₂O₇₃]¹⁴⁻ (1), has been synthesized in aqueous solution and characterized by IR, elemental analysis, TGA and cyclic voltammetry (CV). Single-crystal X-ray analysis was carried out on K_4.5Na_9.5[Sb₂W₂₁Cd(OH)₂O₇₃] · 31H₂O (1a). Polyanion 1 consists of two Cd(W) ions linked to a [Sb₂W₂₀O₇₀]¹⁴⁻ fragment via Cd-O(W) bonds leading to a sandwich-type structure. Interestingly, the polyanion [Sb₂W₂₁Cd(OH)₂O₇₃]¹⁴⁻ (1) as basic building unit is assembled into a one-dimensional (1D) chain-like structure by Cd and W atoms sharing the same site with the 50% occupations, respectively. The electrochemical behavior of 1 was investigated in buffer solution (pH 3.0) by CV. In the potential range between −0.75 and 0.2 V, the compound 1 exhibits the successive redox processes of the addenda atoms (W). The electrocatalytic experiments of the compound show that this compound has good electrocatalytic activity towards the reduction of H₂O₂.