LAUSR

Considering the potential application on preparing electrode and catalyst materials of inorganic–organic hybrid polyoxometalates, a bis-imidazole ligand with carbazole as a connector, 3,6-di(1H-imidazol-1-yl)-9H-carbazole (L), was used for preparing inorganic–organic hybrid polyoxometalates. As a result, three complexes formulated by [NiL2(Mo2O7)] (1), [Cu(H2O)2(HL)2 (β-Mo8O26)]·H2O (2) and [Ni2(H2O)4L2 (CrMo6(OH)5O19)]·6H2O (3) were obtained successfully. Structural analysis indicated that the different polyoxoanions and metal ions showed important influences on the formation of structures. In the presence of Ni2+ ions and heptamolybdate, a 2D network constructed from Ni2+ ions and L ligands was formed in complex 1, in which the [Mo4O14]4− polyoxoanions were encapsulated. But the use of Cu2+ ions led to a 1D chain of complex 2, which was composed of [β-Mo8O26]4− polyoxoanions and mononuclear {CuL2} units. By utilizing [CrMo6(OH)5O19]4− as the inorganic building block, complex 3 showed a 2D (4, 4)-connected layer. Complexes 1–3 could be employed as electrode materials for sensing bromate with the limits of detection of 0.315 μM for 1, 0.098 μM for 2 and 0.551 μM for 3. Moreover, these complexes showed efficient catalytic activity for the selective oxidation of thioethers.