Electronic structures and spectra for triepoxides of fullerene C78O3

The equilibrium structures and relative stabilities of the possible 21 lower‐energy isomers for C₇₈O₃ based on C₇₈ (C_2v) were studied by intermediate neglect of differential overlap (INDO) calculations. It was indicated that the most stable geometry is 28,29,30,31,52,53‐C₇₈O₃, where three oxygen atoms are added to the same hexagon passed by the longest axis of C₇₈ (C_2v) and epoxide structures are formed. Electronic spectra of C₇₈O₃ isomers were investigated based on the optimized geometries. The blue shift of the absorptions for 28,29,30,31,52,53‐C₇₈O₃ compared with that of C₇₈ (C_2v) was rationalized and nature of transition of the peaks discussed. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005