Gas-phase ion-molecule reactions of doubly charged fullerenes with oxygen

Abstract

The gas-phase ion-molecule chemistry of doubly charged fullerene cations (C[sub n][sup 2+] where n = 46, 48, ..., 60 and 70) with neutral oxygen molecules were investigated using a triple quadrupole mass spectrometer. In this paper, we report additions to the fullerene cage structure which result in the formation of C[sub n]O[sup 2+], C[sub n]O[sub 2][sup 2+], and C[sub n]O[sub 3][sup 2+] product ions from the C[sub n][sup 2+] reagent ion. In addition, we also report charge-transfer reactions resulting in the production of C[sub n][sup +] and O[sub 2][sup +] ions, as well as reactive charge-transfer reactions generating C[sub n]O[sup +] and O[sub 3][sup +]. All of these processes are a result of low energy ion-molecule collisions (0.1 - 49 eV[sub lab]). The normalized intensity of the fullerence products exhibit little dependence on size of fullerence clusters examined. However, the reactivities of the fullerenes are found to be highly dependent on the collision energy and the oxygen pressure within the collision cell. 42 refs., 4 figs.