Seminars Archive

1D and 2D polymers via on-surface chemistry: Ullmann coupling as a chemical reaction to growth extended ordered structures

Abstract
Surface-confined polymerization is a bottom-up strategy to create one- and two-dimensional covalent organic nanostructures with a π-conjugated backbone, which are suitable to be employed in real-life electronic devices, due to their high mechanical resistance and electric charge transport efficiency. This is a promising approach that allows the creation of layers with desired architectures and tunable properties changing the molecules used as precursor. One of the main challenges of such an approach is to obtain nanostructures with long-range order, to boost the conductance performances. Most of the exploited chemical reactions use irreversible coupling and, as a consequence, the resulting structures often suffer from poor order and high defect density [1]. This talk will focus on our results about irreversible processes including intermediate states, which are key aspects to control the order of the final nanostructure. I will report on our studies on surface-confined polymerization by using Ullmann coupling reaction obtained by complementary spectroscopic measurements of electronic states (by photoelectron spectroscopy (fast X-ray photoelectron spectroscopy (fast-XPS), angle-resolved photoelectron spectroscopy (ARPES)) and near edge X-ray absorption fine structure (NEXAFS) spectroscopy), scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. These methodologies have allowed to pinpoint a signature of the polymerization reaction and have added new information on the role played by halogen atoms in the process [2-6].
[1] M. Di Giovannantonio and G. Contini, J. Phys.: Condens. Matter 2018, 30, 093001; S. Clair, D. G. de Oteyza, Chem. Rev. 2019, 119, 4717.
[2] M. Di Giovannantonio, M. El Garah, J. Lipton-Duffin, L. Cardenas, Y. Fagot Revurat, A. Cossaro, A. Verdini, D.F. Perepichka, F. Rosei, G. Contini, ACS Nano, 7, 8190 (2013); ACS Nano 2014, 8, 1969.
[3] G. Vasseur, Y. Fagot-Revurat, M. Sicot, B. Kierren, L. Moreau, D. Malterre, L. Cardenas, G. Galeotti, J. Lipton-Duffin, F.Rosei, M. Di Giovannantonio, G. Contini, P. Le Fèvre, F. Bertran, L. Liang, V. Meunier, D. F. Perepichka, Nat. Commun. 2016, 7, 10235.
[4] M. Di Giovannantonio, M. Tomellini, J. Lipton-Duffin, G. Galeotti, M. Ebrahimi, A. Cossaro, A. Verdini, N. Kharche, V. Meunier, G. Vasseur, Y. Fagot-Revurat, D. F. Perepichka, F. Rosei, G. Contini, J. Am. Chem. Soc., 2016, 138, 16696.
[5] G. Galeotti, M. Di Giovannantonio, J. Lipton-Duffin, M. Ebrahimi, S. Tebi, A. Verdini, L. Floreano, Y. Fagot-Revurat, D. F. Perepichka, F. Rosei, G. Contini, Faraday Discussion, 2017, 204, 453.
[6] G. Galeotti, M. Di Giovannantonio, A. Cupo, S. Xing, J. Lipton-Duffin, M. Ebrahimi, G. Vasseur, B. Kierren, Y. Fagot-Revurat, D. Tristant, V. Meunier, D. F. Perepichka, F. Rosei, G. Contini, Nanoscale, 2019, 11, 7682.