Threading of a poly(ethylene glycol) (PEG) chain linked to a perylenediimide unit at one end with a bulky stopper at the other end through an inner cavity of a bisporphyrin-based double-stranded spiroborate helicate was remarkably accelerated in a specific solvent, in which the PEG chain enfolded sodium cations coordinating to the negatively charged spiroborate helicate, thus forming a 1: 1 inclusion complex with the perylenediimide sandwiched between the bisporphyrin unit.