The Topological Transformation of 4 1 Knot to 4 1 2 Link through Supramolecular Fusion.

Realizing topological transformation through supramolecular fusion is particularly challenging, as the self-assembly of disparate components often results in the orthogonal assembly of building blocks into distinct structures rather than the formation of a heteroleptic architecture. This study introduces a topological transformation, transitioning from a figure-eight knot (4 1 knot) to a Solomon link (4 1 2 link) through a supramolecular fusion process. By employing two structurally similar amino acid ligands ( L1 and L3 ) of varying lengths as bridge ligands, we obtained figure-eight knot 1 and a molecular tweezer-like compound 3 when individually complexed with binuclear Cp*Rh acceptor B1 . Our results revealed that subtle modifications to bridge ligands can lead to dramatic changes in their structures and recognition properties. Moreover, we successfully achieved the targeted formation of a heteroleptic Solomon link 4 by blending figure-eight knot 1 and compound 3 in a 1:1 ratio without the need for templates. This procedure effortlessly converted the 4 1 knot into a 4 1 2 link, thus marking a significant advancement in the topological transformation. This work not only marks the construction of the first heteroleptic Solomon link comprising two distinct metallamacrocycles but also demonstrates a process of supramolecular fusion-based topological transformation involving three distinct topological structures.