Further insights into intermediate- and mixed-valency in neptunium oxoanion compounds: structure and absorption spectroscopy of K_2[(NpO_2)_3B_(10)O_(16)(OH)_2(NO_3)_2]

摘要

The reaction of Np(Ⅴ) chloride with molten boric acid results in the disproportionation of Np(Ⅴ) into Np(Ⅳ) and Np(Ⅵ), and the crystallization of K_2[(NpO_2)3B_(10)O_(16)(OH)_2(NO_3)_2]. UV-vis-NIR spectroscopy demonstrates that in addition to the Np(Ⅳ) and Np(Ⅴ) found in the crystal structure, Np(Ⅳ) is also present.