Two-dimensional electronic spectroscopy
In transient absorption (TA), the probe spectrum is dispersed in frequency, but the exciting pump spectrum is not. Detecting molecular dynamics for different excitation wavelengths can be extremely insightful, especially for biological light harvesters and their congested absorption spectra. Two-dimensional electronic spectroscopy (2D-ES) solves this problem elegantly by splitting the excitation event into two pulses, separated by time delay t1. Fourier transformation from t1 to ω1 gives the desired excitation frequency resolution while keeping the time resolution fixed by the duration of the excitation pulses.
With 2D-ES we
- Disentangle energy transfer networks in natural and artificial light-harvesting systems.
- Pinpoint the origin of wavepacket motion to either electronic ground- or excited state.
In a fluorescence-based variant (two-dimensional fluorescence excitaiton spectroscopy, 2D-FLEX)
- We record only the spontaneous emission induced by a femtosecond pump, and hence focus on the electronic excited state.
- We retain the multidimensional character of the signal by double-pulse femtosecond excitation.
Involved group members
Alina Bach
alina.bach@tum.de
Dr. Vivek Nagendra Bhat
vivek.bhat@tum.de
Jakob Kapp
jakob.kapp@tum.de
Further reading
Jonas, D. M. Two-dimensional femtosecond spectroscopy. Annu. Rev. Phys. Chem. 2003, 54, 425-463. DOI: 10.1146/annurev.physchem.54.011002.103907.
Brixner, T.; Mancal, T.; Stiopkin, I. V.; Fleming, G. R. Phase-Stabilized Two-Dimensional Electronic Spectroscopy. J. Chem. Phys. 2004, 121 (9), 4221-4236. DOI: 10.1063/1.1776112.
Own work
Milota, F.; Prokhorenko, V. I.; Mančal, T.; von Berlepsch, H.; Bixner, O.; Kauffmann, H. F.; Hauer, J. Vibronic and Vibrational Coherences in Two-Dimensional Electronic Spectra of Supramolecular J-Aggregates. J. Phys. Chem. A 2013, 117 (29), 6007-6014. DOI: 10.1021/jp3119605.
Heshmatpour, C.; Malevich, P.; Plasser, F.; Menger, M.; Lambert, C.; Šanda, F.; Hauer, J. Annihilation Dynamics of Molecular Excitons Measured at a Single Perturbative Excitation Energy. The Journal of Physical Chemistry Letters 2020, 11 (18), 7776-7781. DOI: 10.1021/acs.jpclett.0c02141.
Jianmin Yang, Maxim F. Gelin, Lipeng Chen, František Šanda, Erling Thyrhaug, and Jürgen Hauer. (2023) Two-dimensional fluorescence excitation spectroscopy: A novel technique for monitoring excited-state photophysics of molecular species with high time and frequency resolution, The Journal of Chemical Physics 159, (7), 074201. DOI: 10.1063/5.0156297