Abstract: The E2 elimination reaction of halohydrocarbon is one of the most important reactions in foundational organic chemistry courses, however, the lack of visual description makes it difficult for undergraduates to understand the mechanism. This study designs a computational chemistry experiment for undergraduate chemistry majors, utilizing quantum chemical calculations to elucidate the detailed mechanism of E2 elimination and its competition mechanism with S_N2 nucleophilic substitution. In this experiment, we obtained thermodynamic and kinetic properties of E2 elimination reaction, helping students understand fundamental concepts such as Zaitsev’s rule, selectivity, reaction thermodynamics, reaction kinetics, transition states, and reaction coordinates, which are integral to both organic and physical chemistry. The primary goal of this experiment is to train students in using computational chemistry methods to solve chemical problems, thereby enhancing their scientific research skills and scientific research literacy.

Key words: Halohydrocarbon, E2 elimination reaction, Zaitsev’s rule, S_N2 nucleophilic substitution, Quantum chemical calculation