Kuck Dietmar, Linke Jens, Teichmann Lisa Christin, Barth Dieter, Tellenbröker Jörg, Gestmann Detlef, Neumann Beate, Stammler Hans-Georg, Bögge Hartmut
Department of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany.
Phys Chem Chem Phys. 2016 Apr 28;18(17):11722-37. doi: 10.1039/c5cp07005h.
The solid-state molecular structure of centrohexaindane (), a unique hydrocarbon comprising six benzene rings clamped to each other in three dimensions around a neopentane core, and the molecular packing in crystals of ·CHCl3 are reported. The molecular Td-symmetry and the Cartesian orientation of the six indane wings of in the solid state have been confirmed. The course and limitation of electrophilic aromatic substitution of are demonstrated for the case of nitration. Based on nitration experiments of a lower congener of , tribenzotriquinacene , the six-fold nitrofunctionalisation of has been achieved in excellent yield, giving four constitutional isomers, two nonsymmetrical ( and ) and two C3-symmetrical ones ( and ), all of which contain one single nitro group in each of the six benzene rings. The relative yields of the four isomers (∼3 : 1 : 1 : 3) point to a random electrophilic attack of the electrophiles at the twelve formally equivalent outer positions of the aromatic periphery of , suggesting electronic independence of its six aromatic π-electron systems. In turn, the pronounced conformational rigidity of the centrohexacyclic framework of enables the unequivocal structural identification of the isomeric hexanitrocentrohexaindanes by (1)H NMR spectroscopy.
报道了中心六茚满（）的固态分子结构，它是一种独特的碳氢化合物，由六个苯环围绕新戊烷核心在三维空间中相互夹持而成，还报道了其·CHCl₃晶体中的分子堆积情况。已证实了其分子的Td对称性以及固态中六个茚满翼的笛卡尔取向。以硝化反应为例展示了的亲电芳香取代反应过程及局限性。基于的一种较低同系物三苯并三喹吖嗪的硝化实验，已以优异产率实现了的六重硝基官能化，得到四种构造异构体，两种非对称的（和）以及两种C₃对称的（和），所有这些异构体在六个苯环的每个环中都含有一个单一硝基。四种异构体的相对产率（约为3∶1∶1∶3）表明亲电试剂在的芳香族外围的十二个形式上等效的外部位置进行随机亲电攻击，这表明其六个芳香族π电子体系在电子上是独立的。反过来，中心六环骨架的显著构象刚性使得能够通过¹H NMR光谱对异构的六硝基中心六茚满进行明确的结构鉴定。
