Helicity is an important structural motif in biological systems, and helical metal complexes have attracted much attention in recent years. 1 Polypyridine based ligands have been studied extensively in this With a series of dicopper(1) complexes of large macrocyclic Schiff-base type ligands [(N2S2)2 donor sets; 30-36-membered cycles] we have dis- covered and studied a new type of double helicity, induced by metal-ion c~ordination.~ A similar metal-ion induced folding ...
