REACTIONS OF SCANDIUM CARBON BINARY CLUSTER IONS C(N)SC-6) WITH O-2 MOLECULES IN AN RF ION-TRAP( (N=2)

The reactions of C(n)Sc+ (n = 2-6) with O2 have been studied by using an rf ion trap. C(n)Sc+ was produced by the laser ablation of a mixed sample of graphite and scandium. Observed reaction product ions were S cO+ for all C(n)Sc+, and ScO2+ only for C(n)Sc+ with odd n. In the cas e of C6Sc+, the loss of 2C neutrals, leading to C4Sc+ production, was also observed. The estimated rate constants of C(n)SC+ + O2 reactions were found to alternate in magnitude with the cluster size; C(n)Sc+ cl usters with even n have rate constants much lower than those with odd n.