Disentangling electron- and electric-field-induced ring-closing reactions in a diarylethene derivative on Ag(1 1 1)

Abstract

Using scanning tunneling microscopy and spectroscopy we investigate the adsorption properties and ring-closing reaction of a diarylethene derivative (C5F-4Py) on a Ag(1 1 1) surface. We identify an electron-induced reaction mechanism, with a quantum yield varying from 10-10 per electron upon variation of the bias voltage from 1-2 V. We ascribe the drastic increase in switching efficiency to a resonant enhancement upon tunneling through molecular orbitals. Additionally, we resolve the ring-closing reaction even in the absence of a current passing through the molecule. In this case the electric-field can modify the reaction barrier, leading to a finite switching probability at 4.8 K. A detailed analysis of the switching events shows that a simple plate-capacitor model for the tip-surface junction is insufficient to explain the distance dependence of the switching voltage. Instead, describing the tip as a sphere is in agreement with the findings. We resolve small differences in the adsorption configuration of the closed isomer, when comparing the electron- and field-induced switching product.

Rotational switches in the two-dimensional fullerene quasicrystal

“…7. From this plot R ' I N , N = 0.68 was determined, which corresponds to the molecular switching behavior reported by Reecht et al (2017). A power N = 1 would suggest a one-electron process.…”

“…It is well known that energy can be transferred from a tunneling electron to a molecule adsorbed on a surface and induce, for example, vibrational and/or rotational excitations (Reecht et al, 2017). Since rotation implies some type of partial transfer of angular momentum, rotational excitation is more complex than vibrational excitation.…”

“…Furthermore, they need to be adsorbed on a flat surface and wired to two metallic electrodes. Some prominent molecule families that are known to fulfill these conditions to a large extent are diarylethenes (Irie et al, 2014;Reecht et al, 2017), azobenzenes (Alemani et al, 2006), and catenanes and rotaxanes (Dichtel et al, 2007;Fahrenbach et al, 2013). Their ability to switch in a controlled manner between two states by conformation change, ring opening/ closing or redox reaction has been thoroughly studied in selfassembled monolayers or as single molecules using scanning tunneling microscopes, in break junctions, and in device geometries (van der Molen & Liljeroth, 2010;Feringa & Browne, 2011;Song et al, 2011;Jia et al, 2016).…”

Photochromic Diarylethenes Designed for Surface Deposition: From Self‐Assembled Monolayers to Single Molecules

“…(Figure g‐h) and also performed conductance switching experiments and imaged dI/dV maps . In a subsequent report on the same compound, the authors showed that the switching could be induced either by tunneling electrons or the electric field between the tip and surface …”

“…[86] In a subsequent report on the same compound, the authors showed that the switching could be induced either by tunneling electrons or the electric field between the tip and surface. [87]…”