Self-Assembly of Charged Supramolecular Sandwiches Formed by Corannulene Tetraanions and Lithium Cations

The reduction of corannulene (C20H10) with excess lithium metal in a strong chelating O-donor solvent, diglyme, leads to the formation of the highly reduced C20H104- anion. However, in contrast to the formation of the sandwich-type supramolecular aggregate [Li-5(C20H104-)(2)](3-) observed in THF, corannulene tetraanions and lithium counterions in diglyme form only contact ion pairs according to Li-7 NMR spectroscopy. Furthermore, the slow dissociation of the premade sandwich [Li-5(C20H104-)(2)](3-) in neat diglyme has been demonstrated by multinuclear NMR spectroscopy. In contrast, the [Li-5(C20H104-)(2)](3-) sandwich can be crystallized from the THF/diglyme mixture as the new crystalline product [Li(THF)(2)(diglyme)(+)[Li-2(THF)-(diglyme)//Li-5(C20H104-)(2)](-), showing a complex ID hybrid architecture according to the single-crystal X-ray diffraction study.