Reduction of Na+ within a {Mg2Na2} Assembly

Abstract

Ionic compounds containing sodium cations are notable for their stability and resistance to redox reactivity unless highly reducing electrical potentials are applied. Here we report that treatment of a low oxidation state {Mg2Na2} species with non-reducible organic bases induces the spontaneous and completely selective extrusion of sodium metal and oxidation of the MgI centers to the more conventional MgII state. Although these processes are also characterized by a structural reorganisation of the initially chelated diamide spectator ligand, computational quantum chemical studies indicate that intramolecular electron transfer is abetted by the frontier molecular orbitals (HOMO/LUMO) of the {Mg2Na2} ensemble, which arise exclusively from the 3s valence atomic orbitals of the constituent sodium and magnesium atoms.