Related Experiment Video
Updated: Jun 19, 2026
08:44
Measurements of Long-range Electronic Correlations During Femtosecond Diffraction Experiments Performed on Nanocrystals of Buckminsterfullerene
Published on: August 22, 2017
Measurement of electron-electron interactions and correlations using two-dimensional electronic double-quantum
Jeongho Kim1, Vanessa M Huxter, Carles Curutchet
1Department of Chemistry, Institute for Optical Sciences and Centre for Quantum Information and Quantum Control, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada.
The Journal of Physical Chemistry. A
|October 13, 2009
Summary
This study introduces two-dimensional double-quantum coherence spectroscopy (2D-DQCS) to map electronic excited states. The technique reveals electron correlation and many-body interactions in molecules.
Area of Science:
- Quantum optics
- Spectroscopy
- Physical chemistry
Background:
- Understanding excited electronic states is crucial for molecular science.
- Electron-electron interactions significantly influence excited-state properties.
- Advanced spectroscopic techniques are needed to probe these complex interactions.
Purpose of the Study:
- To develop and demonstrate a novel two-dimensional optical coherent spectroscopy technique.
- To correlate double excited electronic states with single excited states.
- To investigate electron correlation and many-body effects in excited states.
Main Methods:
- Utilizing multiple, time-ordered ultrashort coherent optical pulses.
- Creating double and single quantum coherences between pulses.
- Applying two-dimensional double-quantum coherence spectroscopy (2D-DQCS).
Main Results:
- The 2D electronic spectra map energy correlations between excited states.
- Measurements on organic dye molecules show energy shifts of tens of millielectronvolts.
- Simulations indicate vibronic transitions enrich the 2D spectra.
Conclusions:
- 2D-DQCS provides quantitative insights into electron-electron interactions.
- The technique elucidates many-body wave functions and electron correlation.
- This method advances the study of excited states and excitons.
Related Concept Videos
01:27π Electron Effects on Chemical Shift: Overview
An applied magnetic field causes loosely bound π-electrons in organic molecules to circulate, producing a local or induced diamagnetic field over a large spatial volume. As the molecules tumble in solution, the field generated by π-electrons in spherical substituents results in a zero net field. However, the net field generated by π-electrons in non-spherical substituents is not zero. The effect of this induced field depends on the orientation of the molecule with respect to B0, resulting in...
01:182D NMR: Overview of Heteronuclear Correlation Techniques
Heteronuclear correlation spectroscopy is an analytical technique that investigates the coupling between different types of nuclei, often a proton and an X-nucleus, such as carbon-13 or nitrogen-15. This method is commonly used in nuclear magnetic resonance (NMR) spectroscopy to gain insights into complex chemical compounds' structural and compositional aspects. A typical heteronuclear correlation spectrum displays X-nucleus chemical shifts on one axis and a proton spectrum on the other axis.
01:192D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)
Heteronuclear single-quantum correlation spectroscopy (HSQC) is a 2D NMR technique that reveals one-bond correlations between hydrogen and a heteronucleus. The HSQC experiment is similar to the heteronuclear correlation experiment (HETCOR) but is more sensitive. In the HSQC spectrum, the proton chemical shift is plotted on the horizontal F2 axis, while the 13C chemical shift is plotted on the vertical F1 axis. The corresponding proton and 13C spectra are also shown. The HSQC contour plot does...
01:14π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds
In aromatic compounds, such as benzene, the circulation of (4n + 2) π-electrons sets up a diamagnetic or diatropic ring current around the perimeter of the molecule. This current induces a magnetic field that opposes the external field inside the ring and reinforces it on the outside. The protons in benzene are deshielded and exhibit high chemical shifts in the range 6.5–8.5 ppm. The shielding effect at the center of the ring is evident in complex aromatic molecules, such as annulenes. In...
01:162D NMR: Overview of Homonuclear Correlation Techniques
Homonuclear correlation spectroscopy (COSY) is a powerful technique used in Nuclear Magnetic Resonance (NMR) spectroscopy to study the correlations between nuclei of the same type within a molecule. It provides information about scalar couplings between adjacent nuclei, which helps determine connectivity and structural information. There are several COSY variants, each with its unique strengths and experimental parameters.
COSY90 is the standard two-dimensional (2D) COSY experiment that...
COSY90 is the standard two-dimensional (2D) COSY experiment that...
01:16UV–Vis Spectroscopy: Molecular Electronic Transitions
In Ultraviolet–Visible (UV–Vis) spectroscopy, the absorption of electromagnetic radiation is used to probe the electronic structure of molecules. This technique provides insights into molecular electronic transitions, particularly the movement of electrons between different molecular orbitals. Radiation is absorbed if the energy of the electromagnetic radiation passing through the molecule is precisely equal to the energy difference between the excited and ground states. During this process,...