Se-Rich Multinuclear Er-Containing Dawson-type Poly(selenotungstate)

A multinuclear Er-containing Dawson-type poly(selenotungstate) (poly(ST)) [H₂N(CH₃)₂]₁₂Na₈Cs₆H₂₆ [Er₁₂Se₁₄W₁₂O₇₂(H₂O)₆(Se₂W₁₄O₅₂)₆]·78H₂O (1) was made by the one-pot assembly with an excess SeO₃^2- source in the reaction system. The polyoxoanion consists of an extremely rare Er₁₂Se₁₄W₁₂O₇₂(H₂O)₆ ({Er₁₂Se₁₄W₁₂}) cluster core surrounded by six tetravacant Dawson-type Se₂W₁₄O₅₂ ({Se₂W₁₄}) fragments, representing the most Se-containing Dawson-type structure so far. Notably, the {Er₁₂Se₁₄W₁₂} cluster exhibits an interesting trefoil-shaped configuration, formed by the condensation of a central Er₃Se₂O₆ ({Er₃Se₂}) cage with three Er₃Se₄W₄O₂₂(H₂O)₂ ({Er₃Se₄W₄}) clusters. The catalytic performance of 1 was evaluated by the oxidative decontamination of 2-chloroethyl ethyl sulfide (CEES) into nontoxic 2-chloroethyl ethyl sulfoxide (CEESO), showing remarkable conversion and selectivity, as well as excellent reusability.