A 12-Crossing Vertex-Fused Double-Triangle [5]Catenane with Programmed Topological Handedness

High-crossing mechanically interlocked molecules are attractive because their dense entanglement can encode unusual stereochemistry, but predictable handedness remains difficult to achieve. Here we show that multiple interlocking in coordination-driven self-assembly gives access to a 12-crossing vertex-fused double-triangle [5]catenane (Rh-2R). X-ray crystallography reveals a composite T(3,3)#T(3,3) topology that can be viewed as two Hopf-link-derived T(3,3) units sharing a central tetranuclear ring. The topological handedness of Rh-2R tracks the coconformational mechanical helicity of the Hopf-link motifs, and the opposite ligand enantiomer gives the mirror-image product both in solution and in the solid state. The solvent composition or concentration shifts the balance between Rh-2R and a less entangled Hopf-linked state (Rh‑2'R), whereas increased ligand steric demand suppresses multiple interlocking. These results reveal that Hopf links can serve as modular stereochemical directors for building and modulating complex topologically chiral links.