Coherence and Ultrafast Dynamics Underpinning Energy Conversion

The parallel and synergistic developments of atomic resolution structural information, new spectroscopic methods, their underpinning formalism, and the application of sophisticated theoretical methods have led to a step function change in our understanding of energy conversion initiated by photosynthetic light harvesting. These new spectroscopic methods, in particular multidimensional spectroscopies, have enabled a transition from recording rates of processes to focusing on mechanism [1]. That work had led to the question of how coherence in chemical systems can be leveraged for function [2]. I will discuss coherence and its role in ultrafast chemical reactions. I will report experiments that illustrate how vibrational wavepackets can serve as a molecular-scale probe to give insight into the reaction coordinate of electron transfer reactions. Valuable insights into electron transfer reactions have been established using Marcus theory. However, a complementary theoretical model explaining how vibrational wavepackets evolve during electron transfer reactions had not yet been established before a “quantum quench” model was posited to address this gap [3].

 

 

[1] Graham R. Fleming and Gregory D. Scholes, Quarterly Reviews of Biophysics 57, e11, 1–29 (2024).

The Development and Applications of Multi-Dimensional Biomolecular Spectroscopy Illustrated by Photosynthetic Light Harvesting

[2] Gregory D. Scholes, Graham R. Fleming, Lin X. Chen, Alán Aspuru-Guzik, Andreas Buchleitner, David F. Coker, Gregory S. Engel, Rienk van Grondelle, Akihito Ishizaki, David M. Jonas, Jeff S. Lundeen, James K.  McCusker, Shaul Mukamel, Jennifer P. Ogilvie, Alexandra Olaya-Castro, Mark A. Ratner, Frank C. Spano, K. Birgitta Whaley, Xiaoyang Zhu: Nature 543, 647–656 (2017).         

Utilizing Coherence to Enhance Function in Chemical and Biophysical Systems 

[3] Alfy Benny, Yuanheng Wang, and Gregory D. Scholes, Journal of the American Chemical Society, 147, 45093-45103.

The Interplay of Vibrational Coherence and Photoinduced Ultrafast Chemical Reactions