Spectroscopic signatures of the carbon buckyonions C_(60)@C_(180) and C_(60)@C_(240): a dispersion-corrected DFT study

摘要

We have investigated, using dispersion corrected DFT methods, the structure and the spectroscopic properties of carbon buckyonions C_(60)@C_(180) and C_(60)@C_(240),C_(60),C_(180) and C_(240) showed a noticeable variation of their geometries in C_(60)@C_(180) and C_(60)@C_(240), upon encapsulation. Inclusion of the dispersion correction term in the calculations has a significant effect on the geometry. C_(60)@C_(180) has a large positive interaction energy, while for C_(60)@C_(240) a negative value is found indicating that only C_(240) can easily accommodate C_(60). In both cases dispersion interactions strongly contribute to the stabilization of the complexes. Vibrational frequencies, electronic transitions and NMR properties have been computed. The results show that encapsulation leads to appreciable variation in the characteristic resonances thus offering a useful tool for a spectroscopic identification of these species.