Designed synthesis of a highly conjugated hexaethynylbenzene-based host for supramolecular architectures

The construction of efficient synthetic functional receptors with tunable cavities, and the self-organization of guest molecules within these cavities through noncovalent interactions can be challenging. Here we have prepared a double-cavity molecular cup based on hexaethynylbenzene that possesses a highly π-conjugated interior for the binding of electron-rich guests. X-ray crystallography, NMR spectroscopy, UV/Vis spectroscopy, fluorescent spectroscopy, cyclic voltammetry, and SEM were used to investigate the structures and the binding behaviors. The results indicated that the binding of a guest in one cavity would affect the binding of the same or another guest in the other cavity. The effect of electron transfer in this system suggests ample opportunities for tuning the optical and electronic properties of the molecular cup and the encapsulated guest. The encapsulation of different guests would also lead to different aggregate nanostructures, which is a new way to tune their supramolecular architectures.