Tetrahedron ( IF 2.1 ) Pub Date : 2017-12-13 , DOI: 10.1016/j.tet.2017.12.020 Erich Kleinpeter , Andreas Koch
The spatial magnetic properties, through-space NMR shieldings (TSNMRS), of the typically anti-aromatic cyclopentadienyl cation, cyclobutadiene, pentalene, s-indacene and of substituted/annelated analogues of the latter structures have been calculated using the GIAO perturbation method employing the nucleus independent chemical shift (NICS) concept and visualized as iso-chemical-shielding surfaces (ICSS) of various size and direction. The TSNMRS values were employed to visualize and quantify the dia(para)magnetic ring current effects in the studied compounds. The interplay of dia(para)magnetic ring current effects due to substitution/annelation caused by heavy exo-cyclic n,π-electron delocalization can be qualified.
中文翻译:
抗芳香结构中的顺磁环电流效应,通过空间磁性能(TSNMRS)进行置换/退火处理
典型的抗芳族环戊二烯基阳离子,环丁二烯,戊烯,s-茚二烯和后一结构的取代/退火类似物的空间磁性能,空间NMR屏蔽(TSNMRS)已使用GIAO扰动方法进行了计算,该方法采用核独立化学位移(NICS)概念,并可视化为各种大小和方向的等化学屏蔽表面(ICSS)。TSNMRS值用于可视化和定量研究化合物中的反(顺)磁环电流效应。可以确定由于重环外n,π-电子离域引起的取代/退火而引起的顺磁环电流效应的相互作用。