Molybdate Complexes of Np(V) with NpO2+ : MoO42– = 1 : 2 and Na+ Cations in the Outer Sphere

Abstract

Two molybdate complexes of Np(V) with Na+ cations in the outer sphere and NpO2+ : MoO42– = 1 : 2 of compositions Na6[(NpO2)2(MoO4)4]·2H2O (I) and Na6[(NpO2)2(MoO4)4]·5H2O (II) have been synthesized and structurally characterized. Two crystallographically independent Np(V) atoms have in both structures a coordination environment in the form of pentagonal bipyramids, the equatorial plane of which are formed by oxygen atoms of MoO42– anions. Each structure has four independent MoO42– anions, two of which are tridentate bridging and two are bidentate-bridging. The structure of I has a layered structure and in structure of II, the main structural motif is the anionic skeleton resulting from the inclusion into the composition of the compound a greater number of water molecules as compared with compound I.