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芳杂环的亲电取代活性及定位效应是许多理论研究的对象。研究的重点多是同系物间的活性比较及分子内的取代定位效应。其规律往往用反应活性部位的电荷数量及分布来解释。量子化学计算结果,一般也符合物理有机的这一传统解释。因此,电荷数量及分布决定分子的取代活性及定位仍是有机化学中普遍接受的观点。不少量子化学活性指标也用于亲电取代活性及定位效应的解释,但一般只局限于同系物的比较,不同母核的芳杂环的亲电取代活性比较则较少为人们所注意。
The electrophilic substitution activity and localization effect of aromatic heterocycles are the objects of many theoretical studies. Most of the research focuses on the comparison of activity between homologs and intramolecular substitution mapping. The law is often explained by the number and distribution of charges in the reactive sites. Quantum chemical calculation results, generally in line with this traditional interpretation of physical and organic. Therefore, the quantity and distribution of charges determine the molecular substitution activity and positioning remains a commonly accepted view in organic chemistry. Many quantum chemical activity indicators are also used to explain the electrophilic substitution activity and localization effect, but generally confined to the comparison of homologues. The electrophilic substitution activities of aromatic nuclei from different mother nuclei are less noticed.