The helical sense of the peptidic parts of a cyclodimeric zinc porphyrin host with helical oligopeptide units (1) determines whether a right‐ or left‐handed oligopeptide guest (2) is selectively bound (see picture). In contrast, enantiomers of nonhelical peptidic guests containing a point chirality are hardly discriminated.

With biologically important "peptide bundling" as the motif, new chromophoric cyclic host 1 was designed, which consists of two zinc porphyrin units that are connected by dynamic peptide helices of nonameric aminoisobutyric acid (Aib) units. Upon inclusion of pyridine-anchored helical peptides between the zinc porphyrin units, 1 displayed an intense exciton-coupled circular dichroism (CD) band at 410-450 nm, whose sign reflected the helical sense of the guest peptides. Studies with conformationally defined dehydrophenylalanine-containing analogues indicated that the dynamic helical chains in the host are stereochemically harmonized with right- or left-handed helices of the guest peptides in a confined nano space, leading to either clockwise- or anticlockwise-twisted geometry (chiroptical output) of the connecting zinc porphyrin chromophores.