Framework materials containing polyoxovanadates as building units: synthesis and characterization of (N 2H 5) 2[M 3(H 2O) 12V 18O 42(EO 4)]·24H 2O (M = Mg, Ca) and Li 6[Mn 3(H 2O) 12V 18O 42(EO 4)]·24H 2O (E = V, S)

Abstract

The reaction of an aqueous solution of lithium vanadate with hydrazinium sulfate results in a dark-colored solution that reacts with magnesium sulfate heptahydrate, calcium sulfate dihydrate, and manganese(II) chloride tetrahydrate to yield single crystals of (N 2H 5) 2[M 3(H 2O) 12V 18O 42(EO 4)]·24H 2O (M = Mg, Ca) and Li 6[Mn 3(H 2O) 12V 18O 42(EO 4)]·24H 2O (E = V, S), respectively. The crystal structures of the new solids consist of interpenetrating three-dimensional networks of {V 18O 42(EO 4)} clusters interlinked via bridging {M(H 2O) 4} (M = Mg, Ca, Mn) groups. The voids in these structures are occupied by lattice water and ion exchangeable cations.