A novel FeC₆₀ adduct in the solid state

Abstract

The 7-{angstrom} diameter cavity in buckminsterfullerene has long been considered as a possible host for various atoms and molecules. There have been several attempts to incorporate metal atoms such as La into this cavity, and these studies have mainly employed mass spectrometry for characterization. The question of whether the metal atom is inside or outside the spheroidal hollow cage in these species has not been fully resolved. Freiser and co-workers have generated an FeC₆₀ complex in the gas phase be means of a ligand-exchange reaction and have also characterized NiC₆₀ and Ni(C₆₀)₂ in the gas phase. Metal complexes of C₆₀ where the metal is present outside the cavity have been prepared by solution methods and characterized. The authors investigated an iron adduct of C₆₀, FeC₆₀ is that where iron atoms were introduced during the contact-arc vaporization of graphite, expecting that this would result in the entrapment of Fe in the cavity. In order to understand some of the unique features of this adduct, the authors have compared its properties with those of solid FeC₆₀ (II), where Fe is clearly bound externally to the fullerene.