Chirality Transfer in 1D Self-Assemblies: Influence of H‑Bonding vs Metal Coordination between Dicyano[7]helicene Enantiomers

• Published in: Journal of the American Chemical Society 2013-10, Vol.135 (41), p.15270-15273
• Main Authors: Shchyrba, Aneliia, Nguyen, Manh-Thuong, Wäckerlin, Christian, Martens, Susanne, Nowakowska, Sylwia, Ivas, Toni, Roose, Jesse, Nijs, Thomas, Boz, Serpil, Schär, Michael, Stöhr, Meike, Pignedoli, Carlo A, Thilgen, Carlo, Diederich, François, Passerone, Daniele, Jung, Thomas A
• Format: Article
• Language: English
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja407315f

Chiral recognition as well as chirality transfer in supramolecular self-assembly and on-surface coordination is studied for the enantiopure 6,13-dicyano[7]helicene building block. It is remarkable that, with this helical molecule, both H-bonded chains and metal-coordinated chains can be formed on the same substrate, thereby allowing for a direct comparison of the chain bonding motifs and their effects on the self-assembly in experiment and theory. Conformational flexure and both adsorbate/adsorbent and intermolecular interactions can be identified as factors influencing the chiral recognition at the binding site. The observed H-bonded chains are chiral, however, the overall appearance of Cu-coordinated chains is no longer chiral. The study was performed via scanning tunneling microscopy, X-ray-photoelectron spectroscopy and density functional theory calculations. We show a significant influence of the molecular flexibility and the type of bonding motif on the chirality transfer in the 1D self-assembly.