Chiral Self-Sorting Process With C2 Symmetric Bisimidazoline Ligands

We have studied the coordination chemistry of chiral imidazoline-based C₂-symmetric ligands with zinc (II) and copper (II). Two types of bisimidazoline ligands were studied, one with the free amine (BIM-H) and the other with the amine protected by a toluene sulfonyl group in position 6 (BIM-Ts). The complexes formed were isolated, purified, and characterized, in particular by X-ray diffraction studies and CD in the case of the enantiopure complexes. By playing with the choice of ligand system (enantiopure or racemate), we were able to show that the selective formation of homoleptic and heteroleptic metal complexes can be controlled by means of the chiral molecular instruction of bisimidazoline ligands.