The Raman Scattering of Uranyl and Transuranium V, VI, and VII Ions

Abstract
The Raman scattering of U(VI), Np(VI), Pu(VI), Am(VI), and Np(V), Am(V) in HClO4 solutions and Np(VII) in a NaOH medium is reported. Direct observation of the polarized ν1 vibration (D∞h symmetry) is observed for the transuranium MO2n+ ions in the V and VI oxidation states. The spectroscopic evidence is consistent with a linear MO2n+ structure for the Np(VII) ion in basic solutions. The trend of the ν1 frequency and the MO stretching force constants with the oxidation is discussed and is correlated with the bond strengths and the stability of the MO2n+ ions.