Cation Controlled Assembly and Transformation of Mono- and Bi-Sulfite Templated Dawson-Type Polyoxotungstates

The Dawson-like polyoxometalate clusters (TEAH)6[H2W18O57(SO3)] (1) and (DMAH)8[W18O56(SO3)2(H2O)2] (2) were synthesized under similar reaction conditions by employing triethanolammonium (TEAH+) and dimethylammonium (DMAH+) as cations, respectively. Crystallographic studies revealed that compound 1 has a compressed, peanut-like {W18} cage containing a single sufilte anion where each cage metal atom supports one terminal oxo-based ligand whereas compound 2 also has a {W18} cage, but four of the eighteen cage metal atoms support two terminal oxo-based ligands with two sulfite anions embedded in the cluster.