Complexation behaviour of chiral tetradentate polypyridines derived from α-pinene

A series of ligands, where two pinene-bipyridine moieties are either connected directly, or through a p-xylene bridge are investigated with respect to their complexation behaviour in solution. The bridged [5,6]-CHIRAGEN[p-xyl] ligands, which are substituted in 5′ or 6′ positions show self-assembly reactions, which lead to similar supramolecular species as the unsubstituted bis-pinene-bipyridines ligands studied before. The directly connected [5,6]-CHIRAGEN[0] derivatives, which are substituted at positions 5′ or 6′, form mononuclear complexes with helical chirality at the metal centre.