A luminescent polyoxoniobate lanthanide derivative {Eu3(H2O)9[Nb48O138(H2O)6]}27-

A europium-containing isopolyoxoniobate with the formula (CN3H6)7K3H17{Eu3(H2O)9Nb48O138(H2O)6}·40H2O is synthesized under the protection of citric acid. ESI-MS spectra show that the polyoxoanion structural unit {Eu3(H2O)9[Nb48O138(H2O)6]}27− is intact in aqueous solution. Moreover, its solid-state luminescence displays a red emission with the long lifetime of 258 μs.