Li+⋯π interaction in coronene–azacrown ether system

The combination of the coronene ring and azacrown ether generated a new kind of host molecule in which the Li+ binding ability originated from the cation–dipole interaction (crown moiety) and the cation–π interaction (coronene ring). Introducing a large π face (coronene ring) enhanced cation binding ability of the crown ether. The NMR, the fluorescence spectra, and ab initio calculations strongly indicated the effect of the cation–π interaction.