Structure and solution properties of the cadmium(II)-substituted tungstoarsenate [Cd4Cl2(B-α-AsW9O34)2]12−

We report on the synthesis and structure of the cadmium(II)-substituted tungstoarsenate [Cd4Cl2(B-α-AsW9O34)2]12− (1). Polyanion 1 consists of two lacunary [B-α-AsW9O34]9− Keggin moieties linked via a rhomblike (Cd4O14Cl2) group leading to a sandwich-type structure. Interestingly, the two external Cd atoms have a terminal Cl ligand, but the derivative with terminal water ligands, [Cd4(H2O)2(B-α-AsW9O34)2]10− (2), can also be prepared as shown by 183W and 111Cd solution NMR.