Computed Encapsulation Energetics for Metallofullerenes

ABSTRACT

Some alkali and alkaline earth metals can now be encapsulated in fullerenes. For example, Li@C₆₀ and Li@C₇₀ can be produced by the low energy bombardment method while Ca@C₇₄, Sr@C₇₄ and Ba@C₇₄ can be prepared by high temprature synthesis. Hence, their computations at higher levels of theory are also of interest. In the report, the computations are carried out on Li@C₆₀, Li₂@;C₆₀ and Li₃@;C₆₀ with the B3LYP and MPWBIK density-functional theory (DFT) treatment in the standard 3-21G and 6-31G^* basis sets. The computed energetics suggests that Li_x@;C₆₀ species could be produced at several small x values if the Li pressure is enhanced sufficiently. The B3LYP DFT approach is also applied to Mg@C₇₄, Ca@C₇₄, Sr@C₇₄ and Ba@C₇₄ and production populations are thus rationalized.

Keywords:

Endohedral fullerenes, carbon-based nanotechnology, molecular modeling, molecular electronic structure, metallofullerene stabilities.