On-surface Synthesis (OSS) is a relatively young subdiscipline of Surface Science focused on the adaptation of traditional wet organic chemistry reactions to surfaces, taking advantage of the catalytic properties of the latter, under the highly controlled conditions afforded by ultra-high vacuum (UHV). It resides on two pillars: the possibility to rationalize, at the atomic and molecular level, the reaction mechanisms involved in the reactions taking place on the surfaces with the help of ab initio theories; and the use of this knowledge to synthesize, following a bottom-up approach, and characterize atomically precise tailored low-dimensional nanostructures exhibiting novel properties thanks to the use of powerful Surface Science characterization techniques, some of them impossible to obtain in wet chemistry due to, for example, their insolubility. This field has shown its validity thanks to a plethora of 0D (fullerenes, nanographenes, etc.), 1D (polymers, graphene nanoribbons, etc.), and 2D (graphene, covalent organic frameworks, metal-organic frameworks, etc.) nanomaterials that have been synthesized from an ample range of reactions such as Ullmann coupling, cyclodehydrogenation, Sonogashira coupling, etc.
At the ESISNA group, we are focused on two main sublines within OSS:
- Unexpected chemistry
Surfaces have shown us that chemistry can behave in a different way when confined in 2D, with the possibility to carry out reactions which otherwise are not feasible (or present a very low efficiency) in solution, sometimes even inducing the lacking selectivity. Currently, we are working on two different projects: the use of atomic hydrogen to catalyze intermolecular reactions without the need of a previous precursor functionalization; and the rich chemistry of alcohol and amino functional groups.
- Synthesis and characterization of distorted graphene nanoribbons (GNRs)
GNRs have revealed as excellent candidates to take graphene into applications where a band gap is needed. Thanks to OSS, atomically precise GNRs of different edge topology (armchair, zigzag and chiral), widths, shapes, and composition have been synthesized. Currently, we are exploring the possibility to induce out-of-plane distortions into GNRs by the incorporation of higher order rings (seven of higher) and studying the new properties induced by this curvature.
- Sánchez-Sánchez, J. I. Martínez, N. Ruiz del Arbol, P. Ruffieux, R. Fasel, M. F. López, P. L. de Andrés, J. A. Martín-Gago. On-surface Hydrogen-Induced Covalent Coupling of Polycyclic Aromatic Hydrocarbons via a Super-hydrogenated Intermediate. J. Am. Chem. Soc., 141, 3550 (2019) Supplementary Cover
- Sánchez‐Sánchez, T. Dienel, A. Nicolaï, N. Kharche, L. Liang, C. Daniels, V. Meunier, J. Liu, X. Feng, K. Müllen, J. R. Sánchez‐Valencia, O. Gröning, P. Ruffieux, R. Fasel. On‐Surface Synthesis and Characterization of Acene‐Based Nanoribbons Incorporating Four‐Membered Rings. Chem. Eur. J. 25, 12074 (2019) Cover Feature and among the top 10% most downloaded papers in the last 12 months
- Ruiz del Arbol, I. Palacio, G. Otero-Irurueta, J. I. Martínez, P. L. de Andrés, O. Stetsovych, M. Moro, P. Mutombo, M. Svec, P. Jelínek, A. Cossaro, L. Floreano, G. J. Ellis, M. F. López, J. A. Martín-Gago. On-surface bottom-up synthesis of azine derivatives displaying strong acceptor behavior. Angew. Chem. Int. Ed., 57, 8582 (2018)
- Cruz, I. Marquez, I. Mariz, V. Blanco, C. Sánchez-Sánchez, J. Sobrado, J. A. Martin-Gago, J. Cuerva, E. Maçôas, A. Campaña. Enantiopure distorted ribbon-shaped nanographene molecule combining two-photon absorption-based upconversion and circularly polarized luminescence. Chemical Science 9, 3917 (2018)