/ Helicity Switching and Chiral Amplification in Double-Helical Monometallofoldamers.

Short-stranded double-helical monometallofoldamers capable of /-switching were constructed by the complexation of two strands, each with two L-shaped units linked by a 2,2'-bipyridine, with a Zn(II) cation. The helix terminals of the "double-helical form" folded by π-π interactions can unfold in solution to equilibrate with the "open forms" that are favored at higher temperatures. Interestingly, the helical chirality of the monometallofoldamers with chiral side chains induced a single-handed helix sense and controlled /-switching depending on achiral solvent stimuli.