Comparative study of the D5h and Ih isomers of Sc3NC@C80 and Sc3N@C80

Stimulated by recent preparation and characterization of two new endohedral cluster fullerenes Sc3NC@C80 and Sc3NC@C78, we have performed systematic density functional studies on the geometrical structures and electronic properties of the D5h isomer of Sc3NC@C80 at the B3LYP/6-31G* level. For the sake of comparison, the geometrical structures and electronic properties of the experimentally available Ih Sc3NC@C80, D5h and Ih Sc3N@C80 have also been investigated at the same level of theory. The results show that the encapsulated Sc3NC cluster adopts a planar structure inside the D5h C80 cage, similar to the case of Ih Sc3NC@C80. D5h Sc3NC@C80 is 18.95 kcal/mol higher in energy than Ih Sc3NC@C80, agreeing well with the relative energies of Sc3N@C80. D5h Sc3NC@C80 has a large HOMO–LUMO gap of 1.77 eV. More importantly, the predicted binding energy (253.0 kcal/mol) of D5h Sc3NC@C80 is even larger than that (247.4 kcal/mol) of the synthesized D5h Sc3N@C80, suggesting a considerable possibility for experimental realization. The Raman spectrometry of this a new endofullerene has been explored to assist future experimental characterization.