Pérez Patricia
Departamento de Ciencias Químicas, Facultad de Ecología y Recursos Naturales, Universidad Nacional Andrés Bello, República 217, Santiago, Chile.
J Org Chem. 2003 Jul 25;68(15):5886-9. doi: 10.1021/jo030125x.
The global and local electrophilicity patterns of a series of 15 diazonium ions have been evaluated using the absolute scale of electrophilicity proposed by Parr et al. (J. Am. Chem. Soc. 1999, 121, 1922). The predicted global electrophilicity pattern of the whole series of diazonium ions correctly compares with the experimental electrophilicity recently determined for these charged electrophiles. The global electrophilicity is then projected into the different potential active sites of the molecular ions using the electrophilic Fukui function. The highest regional electrophilicity power is found at the terminal nitrogen atom of the arenediazonium ions, yet the highest positive charge is located on the nitrogen atom directly attached to the aromatic ring. This result is consistent with the observed reactivity displayed by diazonium ions toward substituted alkenes, thereby suggesting that the formation of the azocarbocation intermediate is mostly orbital rather than charge controlled.
使用帕尔等人（《美国化学会志》，1999年，121卷，1922页）提出的亲电性绝对标度，对一系列15种重氮离子的全局和局部亲电性模式进行了评估。整个重氮离子系列预测的全局亲电性模式与最近针对这些带电亲电试剂测定的实验亲电性正确匹配。然后使用亲电福井函数将全局亲电性投影到分子离子的不同潜在活性位点上。在芳基重氮离子的末端氮原子处发现最高的区域亲电能力，然而最高正电荷位于直接连接到芳环的氮原子上。该结果与重氮离子对取代烯烃显示出的观察到的反应性一致，从而表明偶氮碳正离子中间体的形成主要受轨道控制而非电荷控制。
