Calculated isomeric populations of Er@C₈₂

Abstract

Relative populations of the four energy-lowest IPR (isolated-pentagon-rule) isomers of Er@C₈₂ under the high-temperature synthetic conditions are computed using the Gibbs energy based on characteristics from the density functional theory calculations (B3LYP/6-31+G*∼SDD energetics, B3LYP/6-31G*∼SDD entropy). Two leading isomers are predicted - Er@$C_{2v}(9)$-C₈₂ and Er@$C_s(6)$-C₈₂. The calculated equilibrium isomeric relative populations agree with available observations. As Er@C₈₂ is one of the metallofullerenes recently used as dopants for improvement of efficiency and stability of perovskite solar cells, the calculations should help in finding rules for further selections of fullerene endohedrals for such new applications in photovoltaics.

Keywords:

• Fullerenes
• metallofullerenes
• Er@C₈₂
• isomeric composition
• quantum-chemical calculations

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The reported research has been supported by the National Natural Science Foundation of China (21925104 and 92261204), the Hubei Provincial Natural Science Foundation of China (No. 2021CFA020), and the International Cooperation Key Project of Science and Technology Department of Shaanxi; and by the Charles University Centre of Advanced Materials/CUCAM (CZ.02.1.01/0.0/0.0/15 003/0000417), the MetaCentrum ((LM2010005) and CERIT-SC (CZ.1.05/3.2.00/08.0144) computing facilities. A very initial phase of the research line was supported by the Alexander von Humboldt-Stiftung and the Max-Planck-Institut für Chemie (Otto-Hahn-Institut), too.