COMPUTER SIMULATION OF THE ELECTRONIC STRUCTURE AND REACTIVITY OF MODIFIED C60Xn FULLERENES (n = 2, 4, 6) USING THE CONCEPTUAL DENSITY FUNC-TIONAL THEORY

10.25712/ASTU.1811-1416.2025.04.004

Abstract

A comprehensive computer simulation of a series of C₆₀ fullerene derivatives modified with two, four and six identical functional groups X of different nature (X = -CH₃, -C₂H₅, -C₃H₇, -F, -Cl, -Br, -OH, -OCH₃, -OC₂H₅, -SH, -SCH₃, -SC₂H₅, -NH₂, -NO₂, -COOH, -COCl, -CONH₂, -CN) was performed. The aim of the work was to establish the dependencies between the structure of molecules and their key electronic and reaction descriptors. The calculations were performed using the ORCA 6.1 and Multiwfn 3.8 software packages within the framework of the density functional theory (DFT) using the PBE0-D4 hybrid functional and the def2-SVP (structure optimization) and def2-TZVPD (electron and reaction descriptor calculation) basis sets. Within the framework of the conceptual DFT, the chemical potential μ, hardness η, electrophilicity ω, nucleophilicity N, ionization energies I and electron affinities A were analyzed. For the first time, relative scales of electronic chemical potential <δμ> and hardness <η> were proposed for these systems, allowing to classify the groups by the strength and direction of their influence on the donor-acceptor properties of fullerene structures. A cumulative increase in the influence of substituents upon transition from di- to tetra-derivatives and a deviation from linearity for hexa-substituted structures caused by steric effects were found. It was established that bulky groups with heteroatoms (S, O, N) can become new reaction centers. The results of the work allow one to predict the redox activity and related properties of modified fullerenes and are the basis for targeted design of structures with specified properties.