Formation and Detection of Fullerene Metal Complexes Using Time-Of-Flight Secondary Ion Mass Spectrometry

Abstract

We have found that metal/fullerene adduct ions of the C₆₀ and C₇₀ fullerenes can be formed with silver, gold, rhodium, and palladium by argon-ion bombardment of fullerenes deposited on a metal substrate, with the use of a Time-of-Flight Secondary Ion Mass Spectrometer (TOF-SIMS). The bis and tris metal/fullerene adducts formed include: Ag(C₆₀)₂⁺, AgC₆₀C₇₀⁺, Ag(C₇₀)₂⁺, Ag(C₆₀)₃⁺, Ag(C₆₀)₂C₇₀⁺, AgC₆₀(C₇₀)₂⁺, and Rh(C₆₀)₂⁺. In addition, the monomeric adducts AgC₆₀⁺, AgC₇₀⁺, AuC₆₀⁺, AuC₇₀⁺, RhC₆₀⁺, RhC₇₀⁺, and PdC₆₀⁺ also have been detected. Samples prepared with a raw soot extract gave higher yields of metal/fullerene adducts in TOF-SIMS than those prepared with purified fullerenes. This result may indicate the presence of a matrix component in the raw soot which enhances the formation of fullerene metal adducts. Spectra obtained from the raw soot show peaks at every 24 daltons corresponding to even-numbered carbon clusters. These peaks occur as low as 600 daltons (C₅₀) and as high as 3000 (C₂₅₀).