摘要
总结了立体电子效应在核磁共振波谱学中的应用。分析了立体电子效应对核磁共振波谱中氢化学位移和碳化学位移的影响,解释了一些反常化学位移的本质。当大电负性杂原子对相邻α-和β-氢或碳的化学位移值与其吸电子诱导效应趋势不相符合时,多数情况下是因为含有孤电子对杂原子的给电子nX-σ*立体电子效应,使该氢或碳的电子云密度增加,从而使其化学位移值移向高场。
The applications of the stereoelectronic effect in nuclear magnetic resonance spectroscopy was summarized.The influence of the stereoelectronic effect on proton and carbon chemical shifts in NMR was analyzed,especially for some“abnormal”chemical shifts.When the chemical shift values of heteroatom’s neighboringα-andβ-hydrogen or carbon atoms do not align with the expected trend caused by the electron-withdrawing inductive effect of large electronegative atoms,it is often due to the increase of the electron cloud density of those hydrogen or carbon atoms being affected by the electron-donating nX-σ*stereoelectronic effect of the heteroatoms with a lone pair of electrons.This phenomenon leads to a shift of the chemical shift values towards higher magnetic fields.
作者
白浩彤
许家喜
陈宁
BAI Hao-Tong;XU Jia-Xi;CHEN Ning(College of Chemistry,Beijing University of Chemical Technology,Beijing 100029,China)
出处
《化学教育(中英文)》
北大核心
2025年第4期114-118,共5页
Chinese Journal of Chemical Education
基金
北京化工大学德智体美劳教学改革研究项目(2021BHDJGYB27)
2023年本科教育教学改革研究项目(2023BHDJGY28)。
