Reaction of Atomic Fluorine with Benzene

• Published in: Russian journal of physical chemistry. B 2024-06, Vol.18 (3), p.627-637
• Main Authors: Adamson, S. O., Kharlampidi, D. D., Shtyrkova, A. S., Umanskii, S. Y., Dyakov, Y. A., Morozov, I. I., Stepanov, I. G., Golubkov, M. G.
• Format: Article
• Language: English
• Subjects: Benzene; Chemical reactions; Chemistry; Chemistry and Materials Science; Decomposition reactions; Density functional theory; Elementary Physicochemical Processes; Fluorine; Hydrocarbons; Hydrogen; Low temperature; Physical Chemistry; Quantum chemistry
• ISSN: 1990-7931; 1990-7923
• DOI: 10.1134/S1990793124700192

Benzene is one of the most common classes of industrial chemicals. As a rule, it enters the atmosphere as a result of man-made accidents and during the evaporation of solvents. Benzene and its derivatives are toxic and have a negative impact on the environment and the human body. Therefore, issues related to the transformation of benzene in the atmosphere are of increased interest. In this study, the structures and electronic energies of equilibrium configurations and transition complexes of the C 6 H 6 F and C 6 H 6 F + systems are calculated using the density functional theory. It is shown that the interaction of benzene with atomic fluorine can proceed through two channels: the elimination of hydrogen with the formation of a phenyl radical and the addition of a fluorine atom with the formation of an ipso-fluorocyclohexadienyl radical. It is established that for the dissociation of the ipso-fluorocyclohexadienyl radical into fluorobenzene and atomic hydrogen, it is necessary to expend about 27 kcal/mol. This indicates a low probability of this process occurring at low temperatures. Under experimental conditions, when the temperature of fluorine atoms is about 1000 K, the ipso-fluorocyclohexadienyl radical decomposes to form fluorobenzene. In this case, the occurrence of secondary reactions is unlikely. The conclusions drawn from the analysis of the results of quantum chemical calculations are in close agreement with the experimental data.