Multiple addition patterns in chlorofullerenes C60Cl2n (n=1–4)

Abstract Semiempirical AM1 and ab initio molecular orbital theories have been used to examine the relative stabilities of C 60 Cl 2 n ( n =1–4) isomers. For C 60 Cl 2 , at HF/6-31G* level, 1,4-adduct is 2.21 kcal mol −1 lower in energy than 1,2-adduct. Both AM1 and HF/3-21G calculation results indicate that 1,6,9,18-, 6,12,15,18- and 1,6,11,18-isomers of C 60 Cl 4 are particularly stable, and 1,6,9,12,15,18-C 60 Cl 6 is the most stable isomer of C 60 Cl 6 . Comparing the addition patterns of hydrogenation/fluorination and chlorination of C 60 , it can be concluded that further addition in the vicinity of the previous addition sites are all energetically preferred. And the steric effect may be the primary factor that results in their different addition patterns. The frontier molecular orbital population analysis indicates that the kinetically preferred derivatives and the energetically preferred ones coincide.