A CO 3 2− -containing, dimanganese-substituted silicotungstate trimer, K 9 [H 14 {SiW 10 Mn II Mn III O 38 } 3 (CO 3 )]·39H 2 O

An unprecedented silicotungstate trimer K(9)[H(14){SiW(10)Mn(II)Mn(III)O(38)}(3)(CO(3))]·39H(2)O (1) has been successfully synthesized, in which the CO(3)(2-) resides inside the three Keggin {SiW(10)Mn(II)Mn(III)O(38)} units and the three O atoms serve as μ(2)-O atoms to connect with three Mn(III). Magnetic investigation indicates that 1 exhibits antiferromagnetic coupling.