Chiroptical Control in Helical Receptor-Anion Complexes

Dimers of appropriately arranged anion-responsive pi-conjugated moieties form helical structures by interaction with chiral anions. Terphenyl-bridged dimers of dipyrrolyldiketone boron complexes show chirality induced by binding L-amino acid anions, as observed by circular dichroism (CD) and circularly polarized luminescence (CPL). The preferred configurations of helical structures depend on the geometries of the terphenyl spacer moieties.