Mixed-valent neptunium oligomer complexes based on cation–cation interactions

Abstract

Mixed-valent tri- and tetranuclear complexes of neptunium, [{Np^IVCl₄}{Np^VO₂Cl(THF)₃}₂]·THF and [{Np^IVCl₃}{Np^VO₂(μ₂-Cl)(THF)₂}₃{μ₃-Cl}] (THF = tetrahydrofuran), were synthesised and characterised. Both the complexes are formed via the cation–cation interactions between the Np(IV) centre and the axial oxygens of the neptunyl(V) unit (i.e. trans-dioxo NpO₂⁺ cation), demonstrating the potential of cation–cation interactions for further exploring the oligomer/cluster chemistry of actinides.