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Title: A method for the direct measurement of electronic site populations in a molecular aggregate using two-dimensional electronic-vibrational spectroscopy

Abstract

Two dimensional electronic spectroscopy has proved to be a valuable experimental technique to reveal electronic excitation dynamics in photosynthetic pigment-protein complexes, nanoscale semiconductors, organic photovoltaic materials, and many other types of systems. It does not, however, provide direct information concerning the spatial structure and dynamics of excitons. 2D infrared spectroscopy has become a widely used tool for studying structural dynamics but is incapable of directly providing information concerning electronic excited states. 2D electronic-vibrational (2DEV) spectroscopy provides a link between these domains, directly connecting the electronic excitation with the vibrational structure of the system under study. In this work, we derive response functions for the 2DEV spectrum of a molecular dimer and propose a method by which 2DEV spectra could be used to directly measure the electronic site populations as a function of time following the initial electronic excitation. We present results from the response function simulations which show that our proposed approach is substantially valid. This method provides, to our knowledge, the first direct experimental method for measuring the electronic excited state dynamics in the spatial domain, on the molecular scale.

Authors:
; ; ;  [1];  [2];  [2]
  1. Department of Chemistry, University of California, Berkeley, California 94720 (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
22489636
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 143; Journal Issue: 12; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 77 NANOSCIENCE AND NANOTECHNOLOGY; ABSORPTION SPECTROSCOPY; DIMERS; EXCITATION; EXCITED STATES; INFRARED SPECTRA; NANOSTRUCTURES; PHOTOVOLTAIC EFFECT; PROTEINS; RESPONSE FUNCTIONS; SEMICONDUCTOR MATERIALS; SIMULATION; TIME DEPENDENCE

Citation Formats

Lewis, Nicholas H. C., Dong, Hui, Oliver, Thomas A. A., Fleming, Graham R., E-mail: grfleming@lbl.gov, Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, and Kavli Energy Nanosciences Institute at Berkeley, Berkeley, California 94720. A method for the direct measurement of electronic site populations in a molecular aggregate using two-dimensional electronic-vibrational spectroscopy. United States: N. p., 2015. Web. doi:10.1063/1.4931634.
Lewis, Nicholas H. C., Dong, Hui, Oliver, Thomas A. A., Fleming, Graham R., E-mail: grfleming@lbl.gov, Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, & Kavli Energy Nanosciences Institute at Berkeley, Berkeley, California 94720. A method for the direct measurement of electronic site populations in a molecular aggregate using two-dimensional electronic-vibrational spectroscopy. United States. doi:10.1063/1.4931634.
Lewis, Nicholas H. C., Dong, Hui, Oliver, Thomas A. A., Fleming, Graham R., E-mail: grfleming@lbl.gov, Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, and Kavli Energy Nanosciences Institute at Berkeley, Berkeley, California 94720. 2015. "A method for the direct measurement of electronic site populations in a molecular aggregate using two-dimensional electronic-vibrational spectroscopy". United States. doi:10.1063/1.4931634.
@article{osti_22489636,
title = {A method for the direct measurement of electronic site populations in a molecular aggregate using two-dimensional electronic-vibrational spectroscopy},
author = {Lewis, Nicholas H. C. and Dong, Hui and Oliver, Thomas A. A. and Fleming, Graham R., E-mail: grfleming@lbl.gov and Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 and Kavli Energy Nanosciences Institute at Berkeley, Berkeley, California 94720},
abstractNote = {Two dimensional electronic spectroscopy has proved to be a valuable experimental technique to reveal electronic excitation dynamics in photosynthetic pigment-protein complexes, nanoscale semiconductors, organic photovoltaic materials, and many other types of systems. It does not, however, provide direct information concerning the spatial structure and dynamics of excitons. 2D infrared spectroscopy has become a widely used tool for studying structural dynamics but is incapable of directly providing information concerning electronic excited states. 2D electronic-vibrational (2DEV) spectroscopy provides a link between these domains, directly connecting the electronic excitation with the vibrational structure of the system under study. In this work, we derive response functions for the 2DEV spectrum of a molecular dimer and propose a method by which 2DEV spectra could be used to directly measure the electronic site populations as a function of time following the initial electronic excitation. We present results from the response function simulations which show that our proposed approach is substantially valid. This method provides, to our knowledge, the first direct experimental method for measuring the electronic excited state dynamics in the spatial domain, on the molecular scale.},
doi = {10.1063/1.4931634},
journal = {Journal of Chemical Physics},
number = 12,
volume = 143,
place = {United States},
year = 2015,
month = 9
}
  • Cited by 3
  • Two dimensional electronic spectroscopy has proven to be a valuable experimental technique to reveal electronic excitation dynamics in photosynthetic pigment-protein complexes, nanoscale semiconductors, organic photovoltaic materials, and many other types of systems. It does not, however, provide direct information concerning the spatial structure and dynamics of excitons. 2D infrared spectroscopy has become a widely used tool for studying structural dynamics but is incapable of directly providing information concerning electronic excited states. 2D electronic-vibrational (2DEV) spectroscopy provides a link between these domains, directly connecting the electronic excitation with the vibrational structure of the system under study. In this work, we derivemore » response functions for the 2DEV spectrum of a molecular dimer and propose a method by which 2DEV spectra could be used to directly measure the electronic site populations as a function of time following the initial electronic excitation. We present results from the response function simulations which show that our proposed approach is substantially valid. This method provides, to our knowledge, the first direct experimental method for measuring the electronic excited state dynamics in the spatial domain, on the molecular scale.« less
  • Cited by 10
  • Two-dimensional electronic-vibrational (2DEV) spectroscopy is an experimental technique that shows great promise in its ability to provide detailed information concerning the interactions between the electronic and vibrational degrees of freedom in molecular systems. The physical quantities 2DEV is particularly suited for measuring have not yet been fully determined, nor how these effects manifest in the spectra. In this work, we investigate the use of the center line slope of a peak in a 2DEV spectrum as a measure of both the dynamic and static correlations between the electronic and vibrational states of a dye molecule in solution. We show howmore » this center line slope is directly related to the solvation correlation function for the vibrational degrees of freedom. We also demonstrate how the strength with which the vibration on the electronic excited state couples to its bath can be extracted from a set of 2DEV spectra. These analytical techniques are then applied to experimental data from the laser dye 3,3′-diethylthiatricarbocyanine iodide in deuterated chloroform, where we determine the lifetime of the correlation between the electronic transition frequency and the transition frequency for the backbone C = C stretch mode to be ∼1.7 ps. Furthermore, we find that on the electronic excited state, this mode couples to the bath ∼1.5 times more strongly than on the electronic ground state.« less
  • Light-harvesting complex II (LHCII) serves a central role in light harvesting for oxygenic photosynthesis and is arguably the most important photosynthetic antenna complex. In this article, we present two-dimensional electronic–vibrational (2DEV) spectra of LHCII isolated from spinach, demonstrating the possibility of using this technique to track the transfer of electronic excitation energy between specific pigments within the complex. We assign the spectral bands via comparison with the 2DEV spectra of the isolated chromophores, chlorophyll a and b, and present evidence that excitation energy between the pigments of the complex are observed in these spectra. Lastly, we analyze the essential componentsmore » of the 2DEV spectra using singular value decomposition, which makes it possible to reveal the relaxation pathways within this complex.« less