Successive Neutral C2 Losses from Fullerenes C60 and C70 Ions Using Gas-Phase Fast Particle Bombardment Technique.

Abstract

Successive neutral C2 losses from multiply-charged fullerene ions, C60z+ and C70z+ (z=1~4), have been examined using gas-phase fast particle bombardment (FPB) technique with He, Ar, and isobutane beams. Quadruply-charged ions, C604+ and (C60-C2n)4+ (n = 1~5), were detected by optimizing the experimental conditions. Smallest fragments originated from C2 losses from C60+·, C602+, C603+, and C604+ ions were C36+·, C422+, C443+, and C504+, respectively. The extents of C2 losses from C60z+ and C70z+ (z= 1~4) ions have been compared with each other, using gas-phase FPB and collision-induced dissociation techniques. Metastable peaks originated from C2 and/or C4 losses from C602+ ion were detected. On the basis of the results obtained, kinetics and energetics of C2 losses from C60 ions have been discussed, and the internal energy of C60+· ion produced under gas-phase FPB conditions was roughly estimated.