1. An Arylazopyrazole‐Based N‐Heterocyclic Carbene as a Photoswitch on Gold Surfaces: Light‐Switchable Wettability, Work Function, and Conductance
- Author
-
Bart Jan Ravoo, Kai Sotthewes, Frank Glorius, Christian Gutheil, D. Thao Nguyen, Heinrich F. Arlinghaus, Bonnie J. Tyler, Mowpriya Das, Matthias Freitag, Friederike Schlüter, Nikos L. Doltsinis, Marcus Böckmann, MESA+ Institute, and Physics of Interfaces and Nanomaterials
- Subjects
Molecular switch ,Materials science ,arylazopyrazoles ,Photoswitch ,Photoisomerization ,010405 organic chemistry ,electronics ,self-assembled monolayers ,22/2 OA procedure ,molecular photoswitches ,Self-assembled monolayer ,General Chemistry ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Catalysis ,Surface energy ,0104 chemical sciences ,Microcontact printing ,Desorption ,Work function ,N-heterocyclic carbenes - Abstract
A novel photoresponsive and fully conjugated N-heterocyclic carbene (NHC) has been synthesized that combines the excellent photophysical properties of arylazopyrazoles (AAPs) with an NHC that acts as a robust surface anchor (AAP-BIMe). The formation of self-assembled monolayers (SAMs) on gold was proven by ToF-SIMS and XPS, and the organic film displayed a very high stability at elevated temperatures. This stability was also reflected in a high desorption energy, which was determined by temperature-programmed SIMS measurements. E-/Z-AAP-BIMe@Au photoisomerization resulted in reversible alterations of the surface energy (i.e. wettability), the surface potential (i.e. work function), and the conductance (i.e. resistance). The effects could be explained by the difference in the dipole moment of the isomers. Furthermore, sequential application of a dummy ligand by microcontact printing and subsequent backfilling with AAP-BIMe allowed its patterning on gold. To the best of our knowledge, this is the first example of a photoswitchable NHC on a gold surface. These properties of AAP-BIMe@Au illustrate its suitability as a molecular switch for electronic devices.
- Published
- 2020