Selective Construction of Trefoil knots and a Molecular Borromean Ring Induced by Steric Hindrance of Thioether Ligands

Abstract Two Cp*−Rh III based trefoil knots were obtained in high yield under ambient conditions via the coordination‐driven self‐assembly of semi‐rigid thioether dipyridyl ligand 1,4‐bis[(pyridin‐4‐ylthio)methyl]benzene ( L 1 ), ligand chloranilic acid (H 2 − CA ) and 6,11‐dihydroxytetracene‐5,12‐dione (H 2 ‐ TtDo ) with Cp*Rh III metal corner units, respectively. Furthermore, using the bulkier 4,4′‐{[(2,5‐dimethyl‐1,4‐phenylene)bis(methylene)]bis(sulfanediyl)}dipyridine ( L 2 ) in the place of ligand L 1 in the construction process resulted in the formation of a teranuclear metallacycle and a template‐free Borromean ring in high yields thanks to significantly altered intermolecular forces between the constituent ligands induced by the sterically‐hindering methyl groups of L 2 , as demonstrated via a detailed X‐ray crystallographic analysis and NMR spectroscopy.