Morphological Control of Heteroleptic cis ‐ and trans ‐Pd 2 L 2 L′ 2 Cages

Control over the integrative self‐sorting of metallo‐supramolecular assemblies opens up possibilities for introducing increased complexity and function into a single self‐assembled architecture. Herein, the relationship between the geometry of three ligand components and morphology of three self‐sorted heteroleptic [Pd 2 L 2 L ′ 2 ] 4+ cages is examined. Pd‐mediated assembly of two bis‐monodentate pyridyl ligands with native bite angles of 75° and 120° affords a cis ‐[Pd 2 L 2 L ′ 2 ] 4+ cage while the same reaction with two ligands with bite angles of 75° and 60° gives an unprecedented, self‐penetrating structural motif; a trans‐[Pd 2 (anti‐ L ) 2 L ′ 2 ] 4+ heteroleptic cage with a “doubly bridged figure eight” topology. Each heteroleptic assembly can be formed by cage‐to‐cage conversion of the homoleptic precursors and morphological control of [Pd 2 L 2 L ′ 2 ] cages is achieved by selective ligand displacement transformations in a system of three ligands and at least six possible cage products.