Abstract The bond energy of the C—F bond is significantly higher than that of the C—Cl bond, and the heterolysis in polar solvents does not have thermodynamic advantages. However, in SNAr reactions, the strong electron-withdrawing effect of fluorine atoms can more effectively reduce the electron cloud density of the σ-complex intermediate, thereby decreasing the activation energy of the rate-determining step and granting aromatic fluorides superior kinetic advantages. In the SN1 and SN2 reactions of haloalkanes, the bond energy of the carbon-halogen bond is a critical factor influencing the reaction rate: the lower the bond energy, the higher the kinetic activity. Designing questions based on cases where kinetic and thermodynamic activities align better fits the zone of proximal development for middle school students, enhancing the scientific validity of diagnostic assessments.
SU Zhen-Hua, WU Ying-Zhi, XU Hong. Comparison of Activity of Carbon-Halo Bonds in Nucleophilic Substitution Reactions and Teaching and Preparing Question Suggestions[J]. Chinese Journal of Chemical Education, 2026, 47(5): 114-118.
