Physical-chemical properties of (Znm)@C60 and (Znm)@C70 endohedral metallofullerenes (m = 1-5): A DFT approach

The structural and electronic properties of Zn-m@C-60 and Zn-m@C-70 endohedral metallofullerenes (m = 1-5) were obtained by means of DFT calculations. The whole set of endohedral metallofullerenes (EMFs) are energetically stable despite of they are higher in binding energy than the pristine ones (C-60 and C-70). There is a structural transformation for Zn-4 and Zn-5 clusters, when these are encapsulated inside of C-60 and C-70 fullerenes; the first one changes from trigonal by-pyramid to square pyramid and the second one goes from tetrahedron to planar rhombus, respectively. This effect generates transitions on their electronic behavior, the Zn-m@C-60 systems exhibit two of them: from semiconductor -> conductor -> semiconductor and the Zn-m@C-70 systems present just one: from semiconductor -> conductor. These electronic changes are explained by means of PDOS, HOMO and LUMO iso-surfaces and charge transference. From absorption specters, these EMFs improve the collection of visible and ultraviolet light for both cases, respect to their pristine cases. These physic-chemical properties generate potential applications such as: encapsulation of heavy metals, design of electronic devices, gases sensors and solar cells.

Automated summary

The structural and electronic properties of Zn-m@C-60 and Zn-m@C-70 endohedral metallofullerenes (m = 1-5) were investigated using DFT calculations. Despite having higher binding energies, these endohedral metallofullerenes are energetically stable. Encapsulating Zn-4 and Zn-5 clusters inside C-60 and C-70 fullerenes leads to structural transformations and electronic changes, improving their absorption of visible and ultraviolet light. These properties have potential applications in areas such as heavy metal encapsulation, electronic device design, gas sensors, and solar cells.