Computational Termochemistry Study of the C80 Isomers and Their Endo Lanthanum Complexes by Applying Homodesmotic and Isodesmic Reactions

Abstract

C80 is a fullerene species which appears in different isomeric configurations. A general homodesmotic reaction previously designed to study the energy of fullerenes was implemented, in order to analyze the energy of this family of isomers. These results concur with some of the experimental data, but energy differences referring to all the configurations yield novel propositions about their particular behavior. The corresponding lanthanum complexes are also analyzed here and a new isodesmic reaction was designed for this particular case.

Localization of the valence electron of endohedrally confined hydrogen, lithium and sodium in fullerene cages

“…We focus on the systems X@C N , where X = H, Li, Na, and N = 80, 180. The chosen C 80 isomers were C 80 − D2 − 2 and C 80 − D5d − 1 because they are the only two isomers that have been prepared and characterized as pristine structures [37].…”

Magnetic response properties of carbon nano-onions

“…This isomer has been reported to be the second most stable singlet after the highly distorted D 5d structure. 57,58 The pπ J ind calculations reveal a strong paratropic current density flowing mainly at the equator of the fullerene both inside and outside the cage suggesting that it is antiaromatic (Fig. 2(b)) with a deep minimum in the ring-current profile originating from the local paratropic ring current of the 5-MRs. (Fig.…”

“…10 Previous studies have shown that C 80 has a singly occupied HOMO leading to a Jahn-Teller distortion of the structure and a triplet ground state. 5,6,57,58 NICS(0) calculations yielded positive values in the middle of the 5-MRs and 6-MRs. 5 Unconstrained structure optimization of the singlet state yielded a C 2v structure with a HOMO-LUMO gap of 2.18 eV at the CAM-B3LYP-D3(BJ)/def2-SVP level. This isomer has been reported to be the second most stable singlet after the highly distorted D 5d structure.…”

Process Parameter Optimisation for Endohedral Metallofullerene Synthesis via the Arc-Discharge Method

“…These isomers can have different symmetry, form, and energetic stability. An example of the different structures of the six most stable isomers of C 80 is shown in Figure 1, with D 5d and D 2 being the most stable and abundantly found isomers [9]. Fullerene isomers are also known to have different oxidation potential and chemical reactivity.…”