Synthesis and characterization of one- to three-dimensional compounds composed of paradodecatungstate-B cluster and transition metals as linkers

Three new extended frameworks built from paratungstate and transition metals have been synthesized and characterized. In the compound Na8[{Cd (H2O)2}(H2W12O42)]·32H2O (1), two neighboring paratungstate-B ions [H2W12O42]10− are linked by [Cd(H2O)2]2+ units, leading to the formation of infinite one-dimensional (1D) anion chain [{Cd(H2O)2}(H2W12O42)]n8n−. The anion [{Co(H2O)3}{Co(H2O)4}(H2W12O42)]n6n− of the compound Na6[{Co(H2O)3}{Co(H2O)4}(H2W12O42)]·29H2O (2) shows a layer-like (2D) structure in which paratungstate-B units are linked by CoO6 octahedra, while the anion [{Co(H2O)3}3(H2W12O42)]n4n− of the compound (H3O+)3[{Na(H2O)4}{Co(H2O)4}3(H2W12O42)]·24.5H2O (3) is a three-dimensional (3D) anionic polymer that consists of paratungstate-B units linked by CoO6 octahedra. Compound 3 can reversibly adsorb and desorb water molecules leading to the color reversibly change from pink to violet. The preliminary magnetic measurement and electrochemical properties of compounds are performed. The crystal structure of unexpected product Na4[NiW6O24H6]·13H2O (4) is described here for the rare report of crystal structure information on the Anderson-type polyoxotungstate which has nickel as a heteroatom.