Exhaustively methylated azacalix[4]arene:: Preparation, conformation, and crystal structure with exclusively CH/π-controlled crystal architecture

Described are the preparation, conformation, and crystal structure of exhaustively methylated azacalix[4]arene involving nitrogen atoms as bridging units. NMR and X-ray crystallographic analysis have demonstrated that this novel azacalix[4]arene adopts a 1,3-alternate conformation both in solution and in the solid state. The crystal structure has been characterized solely by intermolecular CH/pi T interactions, by which the azacalix[4]arenes mutually interact with each other outside the cavity to furnish a two-dimensional network structure.