Antiaromaticity: Evidence from magnetic criteria
Antiaromaticity: Evidence from magnetic criteria
复制标题
反芳香性：来自磁性标准的证据
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
P. Schleyer
中科院分区：
文献类型：
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作者：
H. Jiao;P. Schleyer
Antiaromaticity can be characterized by the magnetic criteria (NMR chemical shifts, magnetic susceptibilities and their anisotropies): the behavior is opposite that found in aromatic systems. IGLO computations of these magnetic properties on representative 4n π electron annulenes, benzannulenes, and the bishomoantiaromatic bicyclo[3.2.1]octadienyl cation reveal paramagnetic (positive) susceptibility exaltations Λ. In contrast, aromatic compounds exhibit diamagnetic exaltations and have negative Λ’s. The paramagnetic ring currents in antiaromatic compounds also result in magnetic anisotropy enhancement, opposite in sign to their aromatic counterparts. The downfield NMR chemical shifts of Li+, complexed to the π faces of antiaromatic rings, serve as an additional probe of antiaromaticity. This behavior contrasts with the Li+ upfield shifts of their antiaromatic counterparts.
