Reduction of K<sup>+</sup> or Li<sup>+</sup> in the Heterobimetallic Electride K<sup>+</sup>[LiN(SiMe<sub>3</sub>)<sub>2</sub>]e<sup>–</sup>
Nathan Davison, Paul G. Waddell, Erli Lu
Abstract
High Resolution Image Download MS PowerPoint Slide Given their very negative redox potential (e.g., Li + → Li(0), −3.04 V; K + → K(0), −2.93 V), chemical reduction of Group-1 metal cations is one of the biggest challenges in inorganic chemistry: they are widely accepted as irreducible in the synthetic chemistry regime. Their reduction usually requires harsh electrochemical conditions. Herein we suggest a new strategy: via a heterobimetallic electride intermediate and using the nonbinding “free” electron as reductant. Based on our previously reported K + [LiN(SiMe 3 ) 2 ]e – heterobimetallic electride, we demonstrate the reducibility of both K + and Li + cations. Moreover, we find that external Lewis base ligands, namely tris[2-(dimethylamino)ethyl]amine (Me 6 Tren) or 2,2,2-cryptand, can exert a level of reducing selectivity by preferably binding to Li + (Me 6 Tren) or K + (2,2,2-cryptand), hence pushing the electron to the other cation.