Mutual Monomer Orientation To Bias the Supramolecular Polymerization of [6]Helicenes and the Resulting Circularly Polarized Light and Spin Filtering Properties

Rodríguez, RafaelNaranjo Calderón, CristinaKumar, AnilMatozzo, PaolaDas, Tapan KumarZhu, QirongVanthuyne, NicolasGómez Aspe, RafaelNaaman, RonSánchez Martín, LuisCrassous, Jeanne2024-01-152024-01-152022Rodríguez, R.; Naranjo, C.; Kumar, A.; Matozzo, P.; Das, T. K.; Zhu, Q.; Vanthuyne, N.; Gómez, R.; Naaman, R.; Sánchez, L.; Crassous, J. Mutual Monomer Orientation To Bias the Supramolecular Polymerization of [6]Helicenes and the Resulting Circularly Polarized Light and Spin Filtering Properties. J. Am. Chem. Soc. 2022, 144, 7709-7719 DOI:10.1021/jacs.2c00556.0002-786310.1021/jacs.2c00556https://hdl.handle.net/20.500.14352/93169We report on the synthesis and self-assembly of 2,15- and 4,13-disubstituted carbo[6]helicenes 1 and 2 bearing 3,4,5-tridodecyloxybenzamide groups. The self-assembly of these [6]helicenes is strongly influenced by the substitution pattern in the helicene core that affects the mutual orientation of the monomeric units in the aggregated form. Thus, the 2,15-substituted derivative 1 undergoes an isodesmic supramolecular polymerization forming globular nanoparticles that maintain circularly polarized light (CPL) with glum values as high as 2 × 10–2. Unlike carbo[6]helicene 1, the 4,13-substituted derivative 2 follows a cooperative mechanism generating helical one-dimensional fibers. As a result of this helical organization, [6]helicene 2 exhibits a unique modification in its ECD spectral pattern showing sign inversion at low energy, accompanied by a sign change of the CPL with glum values of 1.2 × 10–3, thus unveiling an example of CPL inversion upon supramolecular polymerization. These helical supramolecular structures with high chiroptical activity, when deposited on conductive surfaces, revealed highly efficient electron-spin filtering abilities, with electron spin polarizations up to 80% for 1 and 60% for 2, as measured by magnetic conducting atomic force microscopy.engAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/Mutual Monomer Orientation To Bias the Supramolecular Polymerization of [6]Helicenes and the Resulting Circularly Polarized Light and Spin Filtering Propertiesjournal article1520-5126https://doi.org/10.1021/jacs.2c00556open access547Química orgánica (Química)2306 Química Orgánica