Work

Power discontinuity and shift of the energy onset of a molecular de-bromination reaction induced by hot-electron tunneling

Year: 2021

Type: article

Abstract: Understanding the mechanism of molecular dissociation under applied bias is a fundamental requirement to progress in (electro)-catalysis as well as in (opto)-electronics. The working conditions of a molecular-based device and the stability of chemical bonds can be addressed in metal-organic junctions by injecting electrons in tunneling conditions. Here, we have correlated the energy of de-bromination of an aryl group with its density of states in a self-assembled dimeric structure of 4'-bromo-4-mercaptobiphenyl adsorbed on a Au(111) surface. We have observed that the electron-energy range where the molecule is chemically stable can be extended, shifting the bias threshold for the rupture of the -C-Br bond continuously from about 2.4 to 4.4 V by changing the electron current. Correspondingly, the power needed for the dissociation drops sharply at 3.6 V, identifying different reaction regimes and the contribution of different molecular resonance states.

Source: Nanoscale

DOI: 10.1039/d1nr04229g

Authors: Ana Barragán, Roberto Robles, Nicolás Lorente, Lucia Vitali

Institutions: University of the Basque Country, Material Physics Center, Donostia International Physics Center, Ikerbasque

Language: English

Topic: Molecular Junctions and Nanostructures

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid