Theoretical studies on the structure and electronic spectra of some isomeric fullerene derivatives C60On (n=2, 3)

Possible isomers of Buckminsterfullerene derivatives C60O2 and C60O3 are st udied with the semiempirical quantum mechanical INDO method. The C60O2 isom er of C-s symmetry, where the epoxy oxygen atoms are on the 6-6 bond of a h exagon, is found most stable. The C60O3 isomer of C-3 nu symmetry with a si ngle epoxy chain connecting both carbons of a 6-6 bond is most stable. Howe ver, the other two isomers of C-2 and C-s symmetries are near as stable. In all cases, the 6-6 carbon-carbon bond in the epoxial ring is not broken. B ased on the structures so identified, the calculated electronic spectra of C60O2, and the C-13-NMR analysis of both C60O2 and C60O3 agree well with ex periment. The calculated electronic spectra of C60O3 are theoretical predic tion. The chemical reactivity of C60O2 and C60O3 is discussed in connection with our calculated results. (C) 2000 John Wiley & Sons, Inc.