Chiral Single-Molecule Potentiometers Based on Stapled ortho- Oligo(phenylene)ethynylenes

We report on the chemical design of chiral molecular junctions with stress-dependent conductance, whose helicity is maintained during the stretching of a single molecule junction due to the stapling of both ends of the inner helix. In the reported compounds, different conductive pathways are observed, with clearly different conductance values and plateau-length distributions, attributed to different conformations of the helical structures. The large chiro-optical responses and the potential use of these molecules as unimolecular spin filters have been theoretically proved using state-of-the-art Density Functional Theory (DFT) calculations, including a fully ab-initio estimation of the CISS-originating spin polarization which is done, for the first time, for a realistic molecular system.

Automated summary

We report on the chemical design of chiral molecular junctions with stress-dependent conductance, whose helicity is maintained during the stretching of a single molecule junction due to the stapling of both ends of the inner helix. The conductance values and plateau-length distributions of the reported compounds show different pathways and conformations of the helical structures. Density Functional Theory calculations demonstrate the large chiro-optical responses and potential use of these molecules as unimolecular spin filters with ab-initio estimation of CISS-originating spin polarization for a realistic molecular system.