N-Heterocyclic Olefins on a Silicon Surface.

Autor: Das M; Westfälische Wilhelms-Universität Münster, Organisch-Chemisches Institut, Corrensstrasse 40, 48149, Münster, Germany., Hogan C; Istituto di Struttura della Materia-CNR (ISM-CNR), Via del Fosso del Cavaliere 100, 00133, Rome, Italy.; Dipartimento di Fisica, Università di Roma 'Tor Vergata', Via della Ricerca Scientifica 1, 00133, Rome, Italy., Zielinski R; Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstrasse 36, D-10623, Berlin, Germany., Kubicki M; Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstrasse 36, D-10623, Berlin, Germany., Koy M; Westfälische Wilhelms-Universität Münster, Organisch-Chemisches Institut, Corrensstrasse 40, 48149, Münster, Germany., Kosbab C; Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstrasse 36, D-10623, Berlin, Germany., Brozzesi S; Dipartimento di Fisica, Università di Roma 'Tor Vergata', Via della Ricerca Scientifica 1, 00133, Rome, Italy., Das A; Westfälische Wilhelms-Universität Münster, Organisch-Chemisches Institut, Corrensstrasse 40, 48149, Münster, Germany., Nehring MT; Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstrasse 36, D-10623, Berlin, Germany., Balfanz V; Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstrasse 36, D-10623, Berlin, Germany., Brühne J; Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstrasse 36, D-10623, Berlin, Germany., Dähne M; Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstrasse 36, D-10623, Berlin, Germany., Franz M; Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstrasse 36, D-10623, Berlin, Germany., Esser N; Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstrasse 36, D-10623, Berlin, Germany.; Leibniz-Institut für Analytische Wissenschaften - ISAS e.V., Schwarzschildstrasse 8, 12489, Berlin, Germany., Glorius F; Westfälische Wilhelms-Universität Münster, Organisch-Chemisches Institut, Corrensstrasse 40, 48149, Münster, Germany.
Jazyk: angličtina
Zdroj: Angewandte Chemie (International ed. in English) [Angew Chem Int Ed Engl] 2023 Dec 11; Vol. 62 (50), pp. e202314663. Date of Electronic Publication: 2023 Nov 09.
DOI: 10.1002/anie.202314663
Abstrakt: The adsorption of N-heterocyclic olefins (NHOs) on silicon is investigated in a combined scanning tunneling microscopy, X-ray photoelectron spectroscopy, and density functional theory study. We find that both of the studied NHOs bind covalently, with ylidic character, to the silicon adatoms of the substrate and exhibit good thermal stability. The adsorption geometry strongly depends on the N-substituents: for large N-substituents, an upright adsorption geometry is favored, while a flat-lying geometry is found for the NHO with smaller wingtips. These different geometries strongly influence the quality and properties of the obtained monolayers. The upright geometry leads to the formation of ordered monolayers, whereas the flat-lying NHOs yield a mostly disordered, but denser, monolayer. The obtained monolayers both show large work function reductions, as the higher density of the flat-lying monolayer is found to compensate for the smaller vertical dipole moments. Our findings offer new prospects in the design of tailor-made ligand structures in organic electronics and optoelectronics, catalysis, and material science.
(© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)
Databáze: MEDLINE
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