Flexible NO2-Functionalized N-Heterocyclic Carbene Monolayers on Au (111) Surface
Authors/Creators
- 1. Institute of Chemistry and The Center for Nanoscience and Nanotechnology, Hebrew University of Jerusalem, Israel
- 2. Department of Chemistry, University of California, Berkeley, California 94720, United States
- 3. Department of Chemistry, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
- 4. CNR-IOM, Laboratorio Nazionale TASC, Basovizza SS-14, Trieste 34012, Italy
Description
The formation of flexible self-assembled monolayers (SAMs) in which an external trigger modifies the geometry of surface-anchored molecules is essential for the development of functional materials with tunable properties. In this work we demonstrate that NO2-functionalized N-heterocyclic carbene molecules (NHCs), which were anchored on Au (111) surface, change their orientation from tilted into a flat-lying position following trigger-induced reduction of their nitro groups. DFT calculations identified that the energetic driving force for reorientation was the lower steric hindrance and stronger interactions between the chemically-reduced NHCs and the Au surface. The trigger-induced changes in the NHCs’ anchoring geometry and chemical functionality modified the work function and the hydrophobicity of the NHCs-decorated Au surface, demonstrating the impact of chemically-tunable NHCs-based SAM on the properties of the metal surface.