Recently, scientists have developed fluoride anion recognition synthetic macromolecules for potential applications in environmental monitoring. However, the actual role of fluoride anion remains highly debated in the reaction of anion-induced electron transfer (ET) to pi-electron-deficient naphthalenediimides. The present study demonstrates that the ET reaction is induced by the complexation of F- with the cation radical formed with the assistance of polar aprotic solvent. The results present an alternative mechanism of the actual role of F- in ET reactions in polar aprotic solvents that could provide novel implications for anion-mediated ET reactions. (C) 2013 Elsevier B.V. All rights reserved.