Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois 60115, USA.
J Am Chem Soc. 2011 Aug 24;133(33):13169-75. doi: 10.1021/ja2046364. Epub 2011 Jul 27.
This Article presents the results from studies related to the chemistry of tricationic superelectrophiles. A series of triaryl methanols were ionized in Brønsted superacids, and the corresponding tricationic intermediates were formed. The trications are found to participate in two types of reactions; both are characteristic of highly charged organic cations. One set of reactions occurs through charge migration. A second set of reactions occurs through deprotonation of an unusually acidic site on the tricationic species. One of the tricationic intermediates has been directly observed by low temperature NMR spectroscopy. These highly charged ions and their reactions have also been studied using density functional theory calculations. As a result of charge migration, electron density at a carbocation site is found to increase with progression from monocationic to pentacationic structures.
本文介绍了与三价超亲电试剂化学有关的研究结果。一系列三芳基甲醇在布朗斯台德超强酸中被电离，形成相应的三价阳离子中间体。这些三价阳离子参与了两种类型的反应；这两种反应都是高度荷电有机阳离子的特征反应。一组反应通过电荷迁移发生。另一组反应通过三价阳离子上异常酸性位的去质子化发生。其中一种三价阳离子中间体已通过低温 NMR 光谱直接观察到。这些高电荷离子及其反应也使用密度泛函理论计算进行了研究。由于电荷迁移，正碳离子位的电子密度随着从单电荷到五电荷结构的进展而增加。
