Veranstaltung

Vortragende Person/Vortragende Personen:
Prof. Dr. Wei Xiong, University of California, San Diego

Diese Veranstaltung ist Teil der Veranstaltungsreihe „GdCh-Vortrag“.

Abstract: Mid-Infrared (MIR) light can interact with molecules by selectively exciting molecular vibrational modes. On one hand, MIR can populate molecular species to specific vibrational states to manipulate chemical reactions; on the other hand, IR spectroscopy has long been used as a molecular sensing tool. In this talk, I will discuss recent advancement in my lab concerning both aspects: controlling molecules and molecular imaging.

In the first half of my talk, I will delve into the dynamics of molecular vibrational polaritons – a hybrid quasiparticle between light and matter through strong coupling interactions.^1-4 Using two-dimensional infrared (2D IR) spectroscopy, we have unambiguously demonstrated that polaritons can efficiently promote energy transfer within or between molecules, subsequently slowing down competing reaction pathways. This research sheds light on the potential roles of polaritons in modifying chemical landscapes and influencing reaction pathways. The second half of my talk will discuss the development of a new IR-based imaging technique - MultiDimensional Widefield Infrared-encoded Spontaneous Emission (MD-WISE) microscopy.⁵ This technique takes advantages of the IR-visible double resonance interactions, which enable using IR photon to modulate fluorescence imaging. As a result, it allows for the distinction of chromophores with overlapping emission spectra by leveraging mid-infrared pulses to encode spatial and temporal data into photoluminescence images. This method shows promises for multiplexing detection channels in biomedical imaging of complex biological entities. These research results highlight how mid-infrared light-matter interaction serves as a powerful mean for both manipulating molecular dynamics and enhancing imaging capabilities, thereby offering new insights into molecular behaviors and interactions at the nano-scale. The implications of these technologies extend across chemistry and biophysics, promising new avenues for research and application in fields ranging from chemical, materials science to biomedical imaging.

1. Xiong, W. Molecular Vibrational Polariton Dynamics: What Can Polaritons Do? Acc. Chem. Res. 2023, 56, 776-786.
2. Xiang, B.; Ribeiro, R. F.; Dunkelberger, A. D.; Wang, J.; Li, Y.; Simpkins, B. S.; Owrutsky, J. C.; Yuen-Zhou, J.; Xiong, W. Two-Dimensional Infrared Spectroscopy of Vibrational Polaritons Proc. Natl. Acad. Sci. U. S. A. 2018, 115, 4845–4850. 
3. Xiang, B.; Ribeiro, R. F.; Du, M.; Chen, L.; Yang, Z.; Wang, J.; Yuen-Zhou, J.; Xiong, W. Intermolecular Vibrational Energy Transfer Enabled by Microcavity Strong Light–Matter Coupling. Science 2020, 368, 665–667. 
4. Chen, T.; Du, M.; Yang, Z.; Yuen-Zhou, J.; Xiong, W. Cavity-Enabled Enhancement of Ultrafast Intramolecular Vibrational Redistribution over Pseudorotation. Science 2022, 378, 790–794. 
5. Yan, C.; Wang, C.; Wagner, J.C.; Ren, J.; Lee, C.; Wan, Y.; Wang, S.E.; Xiong, W. Multidimensional Widefield Inftrared-Encoded Spontaneous Emission Microscopy: Distinguishing Chromophores by Ultrashort Infrared Pulses. J. Am. Chem. Soc. 2024, 146, 1874-1886