关键词: 电子效应, 定位效应, 亲电取代, 拉电子效应, 吸电子效应, 区域选择性

Abstract: The electronic effects of substituents on the benzene ring are the dominant factors influencing their directing effects, which are a key topic in fundamental organic chemistry. In this work, we first summarize the theoretical methods for analyzing predicting the substituent directing effects, as discussed in the literature. Quantum chemistry calculations are then employed to investigate the charge distribution and energetic profiles of several benzene derivatives, with complex electronic effects examined. The findings provide a quantitative understanding of the electronic effects of substituents from a quantum chemical perspective. This research aims to stimulate students' interest in computational chemistry and enhance their ability to approach problems from multiple angles, thereby deepening their understanding of the directing effects of substituents.

Key words: Electronic effect, Directing effect, Electrophilic substitution, Electron-withdrawing effect, Electron-donating effect, Regioselectivity