Chiral Single‐Molecule Potentiometers Based on Stapled <i>ortho</i>‐ Oligo(phenylene)ethynylenes
Ana M. Ortuño, Pablo Reiné, Luı́s Álvarez de Cienfuegos, Irene R. Márquez, W. Dednam, E. B. Lombardi, J. J. Palacios, Edmund Leary, Giovanna Longhi, Vladimiro Mújica, Alba Millán, M. Teresa González, Linda A. Zotti, D. Miguel, Juan M. Cuerva
Abstract
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.