RESUMO
Homochiral triangular prisms, cuboid cages, and capped polyhedral cages are successfully synthesized via coordination-driven self-assembly. Typical tartrate ligands demonstrated notable torsional flexibility and variable coordination numbers, allowing for diverse coordination patterns, including saturated chelation and terminal mono-coordination with half-sandwich rhodium and iridium fragments. The ligand lengths, molar ratios, and metal vertices are meticulously designed and fine-tuned to yield chiral cages with entirely distinct architectures. Tartrate ligand exhibits abundant hydrogen bonding interactions and chiral induction capabilities, these supramolecular assemblies are characterized by single-crystal X-ray diffraction, nuclear magnetic resonance, and circular dichroism spectroscopy. An efficient method is developed for constructing chiral structurally versatile cage-like entities, facilitating self-assembly in complicated multi-component systems.
RESUMO
We have successfully constructed a chiral linear [3]catenane stereoselectively by coordination-driven self-assembly using a ditopic monodentate ligand containing l-valine residues with a binuclear half-sandwich organometallic rhodium(III) unit. Furthermore, by increasing the steric hindrance of the amino acid residues in the ligand, a chiral [2]catenane was obtained, which can be regarded as the factor catenane of the chiral linear [3]catenane from a topological viewpoint. Notably, the resulting molecular catenanes all exhibit complex coconformational mechanical helical chirality and planar chirality ascribed to the point chirality of the ligands. Linear [3]catenanes and [2]catenanes with the opposite chirality can be obtained by using ligands containing the corresponding d-amino acid residues, which have been confirmed by single-crystal X-ray diffraction, NMR, mass spectrometry, and circular dichroism spectroscopy.