Semiempirical molecular dynamics studies of C-60/C-70 fullerene oxides: C60O, C60O2 and C70O

The spectral analysis indicates that all isomers of C60O, C70O and C60O2 ha ve an epoxide-like structure (an oxygen atom bridging across a C-C bond). A ccording to the geometrical structure analysis, there are two isomers of fu llerene monoxide C60O (the 5,6 bond and the 6,6 bond), eight isomers of ful lerene monoxide C70O and eight isomers of fullerene dioxide C60O2. In order to simulate the real reaction conditions at 300 K, the calculation of the different isomers of C60O, C60O2 and C70O fullerene oxides was carried out using the semiempirical molecular dynamics method with two different approa ches: (a) consideration of the geometries and thermodynamic stabilities, an d (b) consideration of the ozonolysis mechanism. According to the semiempir ical molecular dynamic calculation analysis, the probable product of this o zonolysis reaction is C60O. With oxygen bridging over the 6-6 bond (C-2v). The most probable product in this reaction contains oxygen bridging across in the upper part of C-70 (6-6 bond in C70O-2 or C70O-4) an epoxide-like st ructure. C60O2-1, C60O2-3 and C60O2-5 are the most probable products for th e fullerene dioxides. All of these reaction products are consistent with th e experimental results. It is confirmed that the calculation results with t he semiempirical molecular dynamics method are close to the experimental wo rk. The semiempirical molecular dynamics method can offer both the reaction temperature effect by molecular dynamics and electronic structure, dipole moment by quantum chemistry calculation. (C) 1999 Elsevier Science B.V. All rights reserved.