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 SeO32– 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.