Selective electrochemical lithium capture and release using redox-switchable carboranes.

We report the synthesis of a new 1,2-(1,2-bis-sulfoxide-12-crown-4)-ortho-carborane (12C4SOCb) and its selective chemical and electrochemical capture of Li+ from mixed metal (Li+/Na+/K+) solutions upon 2e- reduction to its nido state. The synthesis and characterization of closo-12C4SOCb, nido-, and the Li+-captured nido salt, , are reported. Bulk electrolysis of 12C4SOCb in the presence of various mixed metal alkali salt solutions in organic media, coupled with ICP-OES measurements, reveal highly selective Li+ capture and release against competing ions, enabling its selective separation.