Neptunyl(VI) Nitrate Coordination Polymer with Bis(2-pyrrolidone) Linkers Highlighting Crystallographic Analogy and Solubility Difference in Actinyl(VI) Nitrates

Abstract

NpO2(NO3)2 units are connected by bis(2-pyrrolidone) linker molecules with the trans-1,4-cyclohexyl bridging part (L1) to form a one-dimensional coordination polymer, [NpO2(NO3)2(L1)]n. Molecular and crystal structures of this compound are nearly identical to that of the UO22+ analogue, while its aqueous solubility is greatly enhanced, probably owing to weaker thermodynamic stability of the complexation in NpO22+ compared with that in UO22+.

Keywords

• coordination polymer
• actinides
• neptunium
• crystallography
• solubility
• nuclear fuel recycling