Surface bromination of carbon materials: A DFT study

In this work, we evaluated the reasons of the high reactivity of carbon surface in the bromination reaction. For this purpose, the active centers of carbons were simulated within the density functional theory method. It was shown that all proposed models derived from the honeycomb structure of coronene have edge double C=C bond as an active center of the surface. With an increase in the size of the carbon models, such bonds become shorter, this increases the bond order and, simultaneously, the affinity for the addition reactions becomes significant. The symmetry of models, the defects of the structure or vacancies of carbon atoms do not effect on the length of the edge double C=C bonds. We calculated the reaction thermodynamic for the interaction of C
₅₄
H
₁₈
cluster with dibromine. At these processes, the functional oxygen-containing groups have a certain impact only on the nearest neighboring carbon bonding. The calculation showed that the bromine molecules attack the edge double C=C bond. This way is more energetically favorable than the substitution of hydrogen for bromine.