New Perspectives in Dynamics at Surfaces
Event details
| Date | 07.11.2013 |
| Hour | 16:30 › 17:30 |
| Speaker |
Prof. Alec M. Wodtke Georg-August University of Göttingen and the Max Planck Institute for Biophysical Chemistry, Göttingen, Germany |
| Location | |
| Category | Conferences - Seminars |
Great strides in our understanding of surface chemistry have been achieved over the last two decades due to the advent of computational methods that rely on the Born-Oppenheimer Approximation and exploit the power of the many advances coming from electronic structure theory. However, describing and understanding the atomic scale motion taking place during surface chemical events remains a daunting challenge. Many experiments now show the breakdown of the Born Oppenheimer Approximation for molecular interactions at metal surfaces. This suggests that while energetics derived from modern computational approaches may be reasonably accurate, characterizing the atomic scale motion involved in surface chemical reactions is still an unsolved problem.
In this lecture I will describe experiments capable of revealing dynamical fingerprints of molecular interactions at surfaces where the Born-Oppenheimer Approximation fails.
One of the most powerful experimental tools at our disposal is a form of double resonance spectroscopy, which allows us to define the quantum state of the molecule and measure its velocity both before and after the collision with the surface, providing a complete picture of the resulting energy conversion processes taking place between the molecule and the solid. With such data, we are able to emphasize quantitative measurements that can be directly compared to first principles theories that go beyond the Born-Oppenheimer approximation.
One important outcome of this work is the realization that Born-Oppenheimer breakdown can be induced by simple charge transfer reactions that are common in surface chemistry. Using a newly developed method to control molecular orientation, we are able to observe the orientation dependence of a simple electron transfer reaction.
Another theme of the talk will be the need for developing new tools to study the atomic scale dynamics occurring in collisions at surfaces and the progress being made in Göttingen in this regard. Some of the new methods that I will emphasize are:
1. Scattering of Oriented Molecules From Surfaces
2. Rydberg Tagging of Surface Scattered H-Atoms
3. Generation of Ultra-Short H-Atom Pulse Trains
4. Implementation of Stark Decelerated Beams in Surface Scattering
RELATED REFERENCES
1. Observation of orientation dependent electron transfer in molecule-surface collisions, Nils Bartels, Kai Golibrzuch, Christof Bartels, Chen Li, Daniel J. Auerbach, Alec M. Wodtke, Tim Schäfer*, Proceedings of the National Academy of Science, DOI 10.1073/pnas/1312200110.
2. Multiquantum vibrational excitation of NO scattered from Au(111): Quantitative comparison of benchmark data to ab initio theories of nonadiabatic molecule-surface interactions, Russell Cooper, Christof Bartels, Aleksandr Kandratsenka, Igor Rahinov, Niel Shenvi, Zhisheng Li, Daniel J. Auerbach, John C. Tully Alec M. Wodtke, Angew. Chemie Int. Ed., 124, 5038 –5042 (2012)
3. Inverse velocity dependence of vibrationally promoted electron emission from a metal surface, Hendrik Nahler, Jerry Larue, Jason White, Daniel J. Auerbach and Alec M. Wodtke, Science, 321, 1191-1194 (2008)
4. Conversion of large amplitude vibration to electron excitation at a metal surface, J. White, J. Chen, D. Matsiev, D.J. Auerbach and A.M. Wodtke, Nature 433(7025),503-505, (2005).
5. Vibrational Promotion of electron transfer, Y. Huang, S.J. Gulding, C.T. Rettner, D.J. Auerbach A.M. Wodtke, Science 290, 111-114 (2000)
In this lecture I will describe experiments capable of revealing dynamical fingerprints of molecular interactions at surfaces where the Born-Oppenheimer Approximation fails.
One of the most powerful experimental tools at our disposal is a form of double resonance spectroscopy, which allows us to define the quantum state of the molecule and measure its velocity both before and after the collision with the surface, providing a complete picture of the resulting energy conversion processes taking place between the molecule and the solid. With such data, we are able to emphasize quantitative measurements that can be directly compared to first principles theories that go beyond the Born-Oppenheimer approximation.
One important outcome of this work is the realization that Born-Oppenheimer breakdown can be induced by simple charge transfer reactions that are common in surface chemistry. Using a newly developed method to control molecular orientation, we are able to observe the orientation dependence of a simple electron transfer reaction.
Another theme of the talk will be the need for developing new tools to study the atomic scale dynamics occurring in collisions at surfaces and the progress being made in Göttingen in this regard. Some of the new methods that I will emphasize are:
1. Scattering of Oriented Molecules From Surfaces
2. Rydberg Tagging of Surface Scattered H-Atoms
3. Generation of Ultra-Short H-Atom Pulse Trains
4. Implementation of Stark Decelerated Beams in Surface Scattering
RELATED REFERENCES
1. Observation of orientation dependent electron transfer in molecule-surface collisions, Nils Bartels, Kai Golibrzuch, Christof Bartels, Chen Li, Daniel J. Auerbach, Alec M. Wodtke, Tim Schäfer*, Proceedings of the National Academy of Science, DOI 10.1073/pnas/1312200110.
2. Multiquantum vibrational excitation of NO scattered from Au(111): Quantitative comparison of benchmark data to ab initio theories of nonadiabatic molecule-surface interactions, Russell Cooper, Christof Bartels, Aleksandr Kandratsenka, Igor Rahinov, Niel Shenvi, Zhisheng Li, Daniel J. Auerbach, John C. Tully Alec M. Wodtke, Angew. Chemie Int. Ed., 124, 5038 –5042 (2012)
3. Inverse velocity dependence of vibrationally promoted electron emission from a metal surface, Hendrik Nahler, Jerry Larue, Jason White, Daniel J. Auerbach and Alec M. Wodtke, Science, 321, 1191-1194 (2008)
4. Conversion of large amplitude vibration to electron excitation at a metal surface, J. White, J. Chen, D. Matsiev, D.J. Auerbach and A.M. Wodtke, Nature 433(7025),503-505, (2005).
5. Vibrational Promotion of electron transfer, Y. Huang, S.J. Gulding, C.T. Rettner, D.J. Auerbach A.M. Wodtke, Science 290, 111-114 (2000)
Practical information
- General public
- Free
Organizer
- Dr Frank van Mourik
Contact
- Frank van Mourik
[email protected]