FRESH Lecture: Visualizing single molecules and their reactivity at solid/liquid interfaces
- Dr. Hans Elemans (Radboud University)
- 21 June 2018
- Gorlaeus Building
2333 CC Leiden
Many chemical reactions are catalyzed by metal complexes, and insight in their reaction mechanisms is of fundamental importance for the design of new chemical processes. A wealth of conventional spectroscopic techniques is available to study reaction mechanisms at the ensemble level, but with the emergence of single molecule microscopy and spectroscopy research it has become possible to obtain unique information about reactivity at sub-nanometer scale.
My group aims at studying the behavior of reactive molecules at a surface in a dedicated Scanning Tunneling Microscope (STM) setup. We are able to image self-assembled monolayers of molecules at sub-molecular resolution at the chemically relevant interface of a solid and a liquid, at room temperature and under atmospheric pressure. I will present our methods to construct such monolayers and how we can control the molecular arrangement within them. I will then discuss studies of oxidation reactions mediated by manganese and iron porphyrins. When a monolayer of these porphyrins is exposed to oxygen, STM revealed that a variety of reactions can occur which are expressed as clear changes in catalyst signature in the STM images. The dynamics of these reactions can be monitored for hours. I will demonstrate that this new approach to visualize chemical reactions at the single molecule level reveals unique aspects of reaction mechanisms that remain hidden in conventional ensemble measurements.