Adaptive Cavity‐Enabled Crystalline Chirality in Nanocarbon Cages

Chiral nanocarbons are attractive because their unique chiroptical properties enable advanced optical applications. In this work, we report the discovery that the chirality of nanocarbon cages may be changed in the crystalline state through an “adaptive cavity” effect. This effect allows the use of different crystallization solvents or the introduction of coronene guest molecules to modulate the conformation of the nanocarbon cages. This adaptive behavior permits construction of chiral hierarchical superstructures from achiral building blocks. The resulting chiral crystals exhibit second‐harmonic generation activity and a strong piezoelectric response ( d 33 = 120 pm/V). This work details a novel method for constructing molecular‐level chirality‐controlled solid‐state systems, providing not only proof‐of‐concept examples but also new insights into the development of advanced chiral crystalline nanocarbon materials.