We report an improved synthesis as well as a spectroscopical, structural, and electrochemical characterization of decabromoferrocene (FeC 10 Br 10 ) and relevant side products. Oneelectron oxidation of decabromoferrocene (E 1/2 = 1.095 V vs FeCp 2 0/+ ) was achieved by AsF 5 in liquid SO 2 . The crystal structure of decabromoferrocenium hexafluoroarsenate, [FeC 10 Br 10 ][AsF 6 ], represents the first example of an isolated and structurally characterized perhalogenated ferrocenium salt.