• • M1 macrocycle self-assembles into quadruple-stranded right-handed (P) helices via charge-transfer and CH···π interactions, with single-crystal X-ray diffraction confirming the helical sense and packing mode.
• • Binding of electron-deficient NDI guests triggers a transformation to left-handed (M) double helices, demonstrating a rare crystalline-state multiple-helix conversion with helicity inversion.
• • The macrocycle's adaptive cavity and interstitial voids enable host-guest charge-transfer interactions, which alter molecular geometry and packing modes, leading to opposite chiroptical signals as measured by circular dichroism.
• • This template-free methodology provides a new strategy for constructing multi-stranded π-helices with controlled handedness, potentially enabling applications in chiral optics and supramolecular materials.