Abstract
Regulating multistimulus responses in artificial systems remains a challenge in smart material development. We present a versatile chemical switching system that precisely controls the self-assembly of metal-organic cages via temperature and solvent changes. The key component, cyclo[2](1,3-(4,6-dimethyl)benzene) (4-pyridine)[6](1,3-(4,6-dimethyl)benzene) (CP2), was generated as three atropisomers (1, 2, and 3) with C(s), C(1), and C(2v) symmetries. Thermally, metastable isomers (1 and 2) convert into the stable isomer (3), which reacts with Pd(2+) to form specific molecular cages. Depending on the solvent, either rectangular M(2)L(2) cages (5' and 5) form in 1,4-dioxane or hexagonal M(3)L(3) cages (6) in 1,1',2,2'-tetrachloroethane. The solvent dictates the cage type and enables reversible transformation between cages 5 and 6. Additionally, cage 5', formed from metastable isomer 1, can switch to other cage types (i.e., 5 or 6) depending on temperature and solvent conditions. This multipathway system offers a precise strategy for controlling self-assembly in smart materials.