Authors: Nazario Martı́n | Salvatore Filippone
Source: ECS Meeting Abstracts (article, 2025-07-11)
Field: Chemistry — Organic Chemistry

Molecular Nanographenes: The Search for Enantioselectivity Nanographenes (NGs) have usually been synthetized following a top-down approach by “cutting” a graphene sheet into smaller fragments using chemical or physical methods. Although this methodology starts from readily accessible bulk materials and it is easily scalable, it does not allow a fine control of the properties due to the polydispersion in sizes and shapes of the final material. In contrast, the bottom-up approach in which NGs are grown up from smaller chemical entities using solution-phase benchtop organic synthesis, leads to monodisperse molecules with a precise control on the size and shape, exhibiting fine-tuned optoelectronic properties.[1] Thus, taking advantage of the versatility that provides the set of organic reactions available, and the selectivity of these transformations depending on the reaction conditions, a large number of molecular NGs have been synthetized by design in the recent years. An example of this control is the introduction of out-of-plane defects at will, namely curvature, helicity, or strain, resulting in the presence of chirality as an additional and remarkable structural control. Along the last recent years, we have carried out the synthesis and unveiled the properties of a variety of molecular nanographenes in the search for new chiroptical and optoelectronic properties in all-carbon materials. [2-5] In this presentation some recent and amazing NGs stemming from our research group, with special emphasis on the search for enantioselectivity, will be presented and discussed.[6-7] Acknowledgements Financial support from the Spanish MICIN (Project PID2020-114653RB I00), they also acknowledge financial support from the ERC (SyG TOMATTO ERC-2020-951224) and from the “(MAD2D-CM)-UCM” project funded by Comunidad de Madrid, by the Recovery, Transformation and Resilience Plan, and by NextGenerationEU from the European Union. References [1] J. M. Fernández-García, P. J. Evans, S. Filippone, M. A. Herranz, N. Martín, “Chiral Molecular Carbon Nanostructures”, Acc. Chem. Res . 2019 , 52 , 1565-1574. [2] P. J. Evans, et al., "Synthesis of a Helical Bilayer Nanographene". Angew. Chem. Int. Ed . 2018 , 57 , 6774 –6779. [3] Z. Zhou, J. M. Fernández-García, et al. " Site-Specific Reduction-Induced Hydrogenation of a Helical Bilayer Nanographene with K and Rb Metals: Electron Multiaddition and Selective Rb+ Complexation" . Angew. Chem. Int. Ed. 2022 , 61, e20211574. [4] P. Izquierdo-García, et al. "Helical Bilayer Nanographenes: Impact of the Helicene Length on the Structural, Electrochemical, Photophysical and Chiroptical Properties". J. Am. Chem. Soc. 2023 , 145 , 11599-11610. [5] P. Izquierdo-García, et al. "Twenty Years of Graphene: From Pristine to Chemically Engineered Nano-Sized Flakes" . J. Am. Chem. Soc. 2024 , https://doi.org/10.1021/jacs.4c12819 [6] M. Buendía-Mateos, et al. "Enantioselective synthesis of a two-fold inherently chiral molecular nanographene". Nat. Synth. 2024 , 3 , 545-553. [7] P. Izquierdo-García, et al. “Enantiomerically Pure Helical Bilayer Nanographenes: a Straightforward Chemical Approach” . Submitted for publication. 2024 . Figure 1 Astrobiology ; Chemistry ; Computational biology ; Biology Synthesis and Properties of Aromatic Compounds ; Molecular Junctions and Nanostructures ; Fullerene Chemistry and Applications