红外光谱中取代基对苯环骨架振动吸收峰的影响规律

Effect of Substituents on Benzene Skeleton Vibration in IR Spectra

本文初步地探讨了单取代及对位双取代对苯环骨架振动吸收峰频率和强度的影响规律 ,得出结论 :1给电子单取代基随给电子能力增强使苯环骨架振动吸收峰 16 0 0 cm-1增强 ,而吸电子基则相反。 2卤素作为单取代基时 ,使苯环骨架伸缩振动产生强红外吸收峰 ;且随卤素电负性增强吸收峰频率向高波数移动。 3对位取代基为不同类型时 ,16 0 0 cm-1处显强峰 ,而为同一类型时 ,当电子效应相近或相同时 ,16 0 0 cm-1处吸收峰很弱或根本无吸收峰。并讨论了产生这些现象的原因。

The effect of various substituents in infrared spectroscopy on benzene was studied and discussed.The results show that the monosubstituents including both electron donating groups and withdrawing groups, particularly the halogen atoms, have effects on the absorption of benzene skeleton vibration in infrared spectroscopy,as well as the para substituents.Reasons resulting in these phenomena were discussed.