Guest‐Directed Navigation of a Ligand Conformational Landscape Enables Palladium‐Organic Cage–Bowl–Helicate Interconversion

ABSTRACT Biological systems regulate molecular function by reshaping conformational energy landscapes in response to external stimuli. Translating this principle into artificial supramolecular systems remains challenging, particularly when multiple structurally distinct states must be accessed using a single class of stimulus. Here, we report a conformationally adaptive ligand L comprising two 2,4,6‐tris(4‐pyridyl)‐1,3,5‐triazine (TPT) panels connected by a conformationally flexible 3,3′‐disubstituted biphenyl spacer. Coordination of L with (en)Pd(II) affords a discrete Pd 4 L 2 cage 1 . Distinct guests redirect the assembly landscape along divergent pathways: 6‐methylcoumarin ( G1 ) induces the bowl‐shaped Pd 4 L 2 complex ( G1 ) 4 ⊂ 2 , whereas 1‐adamantanol ( G2 ) selects the Pd 6 L 3 triple‐stranded helicate ( G2 ) 8 ⊂ 3 . Cage 1 , bowl 2 , and helicate 3 correspond to trans‐/cis‐, cis‐/cis‐, and cis‐/trans‐ combinations of the biphenyl spacer and TPT‐panel orientations, respectively. Guest‐exchange experiments reveal path‐dependent interconversion: G1 converts helicate 3 toward a mixture of cage 1 and bowl 2 , whereas guest removal restores cage 1 , enabling G2 to redirect it back to helicate 3 . Thus, the system can be precisely navigated among cage, bowl, and helicate architectures solely through guest addition, removal, and exchange. A 4,4′‐biphenyl‐linked analogue shows no comparable conversion. These results establish a guest‐addressable three‐state self‐assembly landscape in which distinct combinations of ligand cis‐/trans‐ conformations encode divergent supramolecular architectures.