Resolution of Intramolecular Dipoles and a Push-Back Effect of Individual Molecules on a Metal Surface

Trishin S, Müller T, Rolf D, Lotze C, Rietsch P, Eigler S, Meyer B, Franke KJ (2022)

Publication Type: Journal article

Publication year: 2022

Journal

Journal of Physical Chemistry C American Chemical Society

Abstract

Molecules consisting of a donor and an acceptor moiety can exhibit large intrinsic dipole moments. Upon deposition on a metal surface, the dipole may be effectively screened and the charge distribution altered due to hybridization with substrate electronic states. Here, we deposit ethyl-diaminodicyanoquinone molecules, which exhibit a large dipole moment in the gas phase, on a Au(111) surface. Employing a combination of scanning tunneling microscopy and noncontact atomic force microscopy, we find that a significant dipole moment persists in the flat-lying molecules. Density functional theory calculations reveal that the dipole moment is even increased on the metal substrate as compared to the gas phase. We also show that the local contact potential across the molecular islands is decreased by several tens of meV with respect to the bare metal. We explain this by the induced charge-density redistribution due to the adsorbed molecules, which confine the substrate's wavefunction at the interface. Our local measurements provide direct evidence of this so-called push-back or cushion effect at the scale of individual molecules.

Authors with CRIS profile

Tobias Müller Interdisziplinäres Zentrum für Molekulare Materialien Bernd Meyer Professur für Computational Chemistry

Additional Organisation(s)

Graduiertenkolleg 2423 Skalenübergreifende Bruchvorgänge: Integration von Mechanik, Materialwissenschaften, Mathematik, Chemie und Physik Computer-Chemie-Centrum

Involved external institutions

Freie Universität Berlin

Germany (DE)

How to cite

APA:

Trishin, S., Müller, T., Rolf, D., Lotze, C., Rietsch, P., Eigler, S.,... Franke, K.J. (2022). Resolution of Intramolecular Dipoles and a Push-Back Effect of Individual Molecules on a Metal Surface. Journal of Physical Chemistry C. https://dx.doi.org/10.1021/acs.jpcc.2c00334

MLA:

Trishin, Sergey, et al. "Resolution of Intramolecular Dipoles and a Push-Back Effect of Individual Molecules on a Metal Surface." Journal of Physical Chemistry C (2022).

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