Sulfoxide-Induced Homochiral Folding of o-OPEs by AgI Templating: Structure and Chiroptical Properties

Abstract

A new family of homochiral silver complexes based on carbophilic interactions with ortho-phenyleneethynylene (o-OPE) scaffolds containing up to two silver atoms is described. These compounds represent a unique class of complexes with chirality at the metal. Chiral induction is based on the inclusion of chiral sulfoxides which allow an efficient transfer of chirality to the helically folded o-OPE, leading to CPL and VCD active compounds. In the presence of AgI cation carbophilic interactions dominate, promoting helical structures with a defined helicity. This is one of the very scarce examples of the use of such interactions in the attractive field of abiotic foldamers. The switching event has been extensively studied using different chiroptical techniques including CD, CPL and VCD, also representing one of the few CPL switches described in literature.