A water-soluble cage containing three naphthalenediimide (NDI) units was synthesized in a one-pot manner without chromatographic purification, during which six irreversible C–N bonds formed simultaneously via an SN2 reaction. The cage was observed to be capable of accommodating a variety π-electron rich guests in a peripheral manner in water. However, for linear guests including I3− and I2, the cage is able to form an inclusion complex. Besides, in the solid state, the cage can absorb vapor of I2.
