C۲۴ nanocatalyst effects on the collision between phenylenediamine and formic acid in the benzimidazole synthesis mechanism: A molecular dynamics study

Very recently, the mechanism of benzimidazole synthesis was studied in the presence and absence of a C۲۴ fullerene-like nanocatalyst using density functional theory (DFT). Transition-state analyses with linear and quadratic synchronous transit (LST/QST) indicate that the activation energy for the first elementary step decreases from ۴۱.۹۳ to ۱۸.۵۷ kcal·mol-۱ in the presence of the C۲۴ catalyst. In addition to activation energy, collision frequency—an important factor in determining the rate constant—requires sampling over an ensemble of particles, a capability beyond the reach of standard DFT alone. Therefore, molecular dynamics (MD) simulations are employed to investigate formic acid–phenylenediamine contacts within an ensemble, both with and without the C۲۴ catalyst. The results show that the radial distribution function for contacts involving the relevant functional groups exhibits higher peak intensities in the presence of the C۲۴ catalyst, indicating enhanced interaction between formic acid and phenylenediamine when the catalyst is present. Together, these findings provide a more complete picture of how C۲۴ modulates the benzimidazole formation mechanism by influencing both the energetic landscape and the dynamical encounters between reactants.

کلیدواژه ها:

Collision frequency ، C۲۴ catalyst ، Radial distribution function ، Diffusion coefficient