Lanthanide supramolecular helical diastereoselective breaking induced by point chirality: mixture or P-helix, M-helix.

The self-assembly of lanthanide (europium or lanthanium) bimetallic triple helicates from two closely related chiral ligands resulted in a very different supramolecular phenomenon. One gave rise to significantly diastereoselective formation of a triple helicate, whereas the other led to diastereoselective breaking to generate a mixture of P and M diastereomers in similar to 1 : 1.1 ratio. The first X-ray crystal structure of a chiral ligand based lanthanide triple-helicate indicates that successive CH-pi interactions were found to maintain the supramolecular helical structure.