Spectroscopic Investigation of a Series of Sodium Lanthanide Decatungstates, Na7H2Ln(III)(W5O18)2×nH2O (Ln: La-Yb): The Contribution of 4fn Electrons to Bonding Interaction Among Ln(III) and Polyoxotungstates.

Abstract A series of sodium lanthanide decatungstates, Na7H2Ln(III)(W5O18)2·nH2O (Ln-La-Yb) was synthesized and characterized by spectroscopic analyses. The 183W-NMR chemical shifts for the W adjacent to Ln(III) correlated well with the contact parameter in the lanthanide induced shifts, 〈Sz〉, which had been theorized by Golding. The FT-Raman stretching frequencies for the Ln-O-W bonding also correlated with the theoretical magnetic moments induced from the 4fn electrons in the lanthanide ions in addition to the ionic radii of Ln(III). A direct contribution of the 4fn electrons to the bonding interaction among Ln(III) and the oxotungstates is suggested.