The way of stabilizing non‐IPR fullerenes and structural elucidation of C 54 Cl 8

Recently, a new non‐IPR chlorofullerene C 54 Cl 8 was isolated experimentally (Science 2004, 304, 699). To explore the ways to stabilize non‐IPR fullerenes, the authors studied all of the possible isomers of C 54 fullerene and some of the C 54 Cl 8 isomers at PM3, B3LYP/3‐21G, and B3LYP/6‐31G* levels. Combined with analysis of pentagon distributions, bond resonance energies, and steric strains, C 54 :540 with the least number of 5/5 bonds was determined to be the thermodynamically best isomer for the C 54 Cl 8 . Based on C 54 :540, the most probable structure of the experimental C 54 Cl 8 was elucidated. The results suggested one of the necessary conditions of stabilizing non‐IPR fullerenes: chemical derivatizations of either endohedral complexation or exohedral addition need to sufficiently stabilize all of the kinetically unstable 5/5 bonds of the cages. © 2007 Wiley Periodicals, Inc. J Comput Chem 28: 795–801, 2007