Electrospray and Laser Desorption Ionization Studies of C60O and Isomers of C60O2

The reaction of C{sub 60} with ozone in toluene results in the formation of C{sub 60} oxides. C{sub 60}O and two isomers of C{sub 60} O{sub 2} were isolated; they both have the 423 nm absorption peak characteristic of an epoxide structure between adjacent 6,6-rings in C{sub 60}. Intact molecular ions are generated by electrospray ionization (ESI) without fragmentation. The enhanced ESI sensitivity of the higher oxides reflects the increase in electron affinity upon oxidation. In contrast to ESI, odd-numbered fragments are observed in laser desorption ionization (LDI) of C{sub 60}O. The two isomers of C{sub 60}O{sub 2} show different intensity distributions of the same fragment ions in LDI, suggesting different distances between the two oxygen atoms in them. Mechanisms are proposed for the formation of the two isomeric forms of C{sub 60}O{sub 2} and for mass spectrometric fragmentation processes. 14 refs., 5 figs.