Anion-Induced Electron–Transfer Reduction of Li@C₆₀ with Tetrathiafulvalene Calix[4]pyrrole

Abstract

No electron transfer from tetrathiafulvalene calix[4]pyrrole (TTF-C4P) to lithium encapsulated fullerene (Li@C₆₀•PF₆) occurs in a mixed solution (benzonitrile : chloroform = 1:1,v/v). Addition of tetraethylammonium chloride results in formation Li@C₆₀ radical anion and TTF-C4P radical cation by the binding of chloride at the C4P moiety, and following electron transfer from TTF-C4P to Li@C₆₀ to form the triplet radical ion pair. The triplet radical ion pair was identified by the EPR measurements. Disappearance of radical ion pair was observed upon addition of tetraethyl ammonium salt via back electron transfer.