School of Chemistry and BIO-21 Institute, University of Melbourne, Parkville 3010, Victoria, Australia.
Molecules. 2013 Sep 25;18(10):11705-11. doi: 10.3390/molecules181011705.
Selenium substituents which are disposed β to an electron deficient centre, such as a carbocation p-orbital, or the π* orbital of an electron deficient p-system, interact in a stabilising way by a combination of C-Se hyperconjugation (σ(Se-C)-π* interaction), and a through-space homoconjugative n(Se)-π* interaction. The relative importance of these two modes of interaction is dependant on the electron demand of the cation, with hyperconjugation predominating for low electron demand systems, and the n(Se)-π* interaction predominating for high electron demand cations.
处于缺电子中心（如碳正离子的 p 轨道，或缺电子 p 体系的π轨道）β位的硒取代基通过 C-Se 超共轭（σ(Se-C)-π相互作用）和通过空间的同共轭 n(Se)-π相互作用以稳定的方式相互作用。这两种相互作用模式的相对重要性取决于阳离子的电子需求，对于低电子需求系统，超共轭占主导地位，而对于高电子需求阳离子，n(Se)-π相互作用占主导地位。
