Actinide structural studies. Part 10. A mixed oxidation state neptunyl chloride: crystal structure of Cs7[NpVO2][NpVIO2]2Cl12

Abstract

The crystal structure of Cs₇[Np^VO₂][Np^VIO₂]₂Cl₁₂ has been determined. It is cubic, with a= 15.084(4)Å, space group I3d, and R= 0.035 for 1 674 observed [I/σ(I) 3.0] reflections. Only one neptunium position is found, containing two Np^VI and one Np^V, substitutionally disordered. They are octahedrally co-ordinated, with Np–O 1.790(15) and Np–Cl 2.685(5)Å, intermediate between the values for Np^V and Np^VI.