This Account summarizes the results obtained in our research group on the intra- and intermolecular organoiron activation of substrates by combining the coordination of arenes by CpFe +/0 and electron and/or proton transfer. The concepts involved are those of electron and proton reservoirs, activation of O 2 by single electron transfer in solution, mimic and inhibition of the reactivity of superoxide radical anion, materials synthesis (for instance fullerene anions), electronic communication between two metals connected by a hydrocarbon bridge, activation of arene ligands for multiple functionalization, giant dendrimer synthesis and electron transfer in catalysis (redox and electron-transfer-chain).