Sandwich-type Inorganic-Organic Hybrid Solids of Iso-polyvanadate Clusters and Decamethylcucurbit[5]uril.

Three sandwich-type inorganic-organic hybrid solids based on iso-polyvanadate cluster, {V4O12}4-, {H2V6O18}4-, or {H2V10O28}4-, and decamethylcucurbit[5]uril (Me10CB[5]) have been synthesized under hydrothermal conditions. In the structures of (NH4)4[(V4O12)·(Me10CB[5]@0.5H2O)2]·∼15H2O (1) and (NH4)4[(H2V10O28)·(Me10CB[5]@H2O)2]·∼16H2O (3), tetranuclear {V4O12}4- or decanuclear {H2V10O28}4- clusters are sandwiched by (NH4)2@Me10CB[5] closed molecular capsules, through hydrogen-bonding interactions, whereas compound 2, formulated as Li4(H2O)6[(H2V6O18)·(Me10CB[5]@H2O)2]·∼14H2O, is built by hexanuclear {H2V6O18}4- clusters that are covalently sandwiched by Li2@Me10CB[5] half-open molecular capsules in a way similar to thoset of 1 and 3. Compounds 1-3 represent rare examples of sandwich-type polyoxometalate (POM)-based materials in which POM units are inserted at the inner sphere by either hydrogen or covalent bonds. Compound 2 has shown rational photocatalytic activity toward the degradation of methyl orange solutions under visible light. [ABSTRACT FROM AUTHOR]