Luminescence from neptunyl(VI) species in solution

The luminescence from the neptunyl(VI) ion and its polyoxometallate complexes has been investigated in solution for the first time. Emission occurs in the near-IR and is quenched effectively by O-H oscillators in the hydrated ion. The polyoxometallate complexes exclude solvent from the neptunyl coordination sphere and have much more intense and longer-lived emission spectra.