Related Experiment Video
Updated: Jun 19, 2026
06:53
Photoelectron Imaging of Anions Illustrated by 310 Nm Detachment of F−
Published on: July 27, 2018
Anion Photoelectron Spectroscopy and Quantum Chemical Study in ThF.
Xiao-Gen Xiong1,2, Changwu Dong3, Hongtao Liu3
1Sino-French Institute of Nuclear Engineering and Technology, Sun Yat-sen University, Zhuhai 519082, P. R. China.
The Journal of Physical Chemistry Letters
|June 18, 2026
Summary
Researchers measured the electron affinity of Thorium Fluoride anion (ThF-) using photoelectron spectroscopy. Calculations confirmed experimental findings, providing accurate energy values for ThF- detachment.
Area of Science:
- Relativistic quantum chemistry
- Molecular spectroscopy
- Chemical physics
Background:
- Thorium Fluoride anion (ThF-) is a molecule of interest in relativistic chemistry.
- Understanding its electronic properties is crucial for theoretical and experimental studies.
Purpose of the Study:
- To experimentally determine the electron affinity (EA) of ThF-.
- To theoretically calculate the adiabatic detachment energy (ADE) and vertical detachment energy (VDE1) of ThF-.
- To assign observed spectroscopic bands to relativistic electronic states of ThF.
Main Methods:
- Photoelectron spectroscopy was employed for experimental measurements.
- Relativistic quantum chemistry calculations, including CCSD(T) and SO-CASPT2 methods, were utilized for theoretical analysis.
Main Results:
- The experimental electron affinity (EA) of ThF- was determined to be 0.680 ± 0.007 eV.
- Calculated ADE and VDE1 values were 0.558 eV and 0.592 eV, respectively.
- Spectroscopic bands were successfully assigned to relativistic electronic states of ThF, showing good agreement with experimental data (within 0.08 eV).
Conclusions:
- The study successfully combined experimental and theoretical methods to investigate the photodetachment of ThF-.
- Accurate EA, ADE, and VDE1 values were obtained, validating the employed computational methods.
- The findings contribute to a deeper understanding of relativistic effects in molecular systems.
Related Concept Videos
01:23Atomic Spectroscopy: Absorption, Emission, and Fluorescence
Atomic spectroscopy is a vital tool in elemental analysis, both qualitatively and quantitatively. It can be broadly divided into optical spectroscopy, mass spectroscopy, and X-ray spectroscopy methods. The optical spectroscopic methods are atomic absorption spectroscopy (AAS), atomic emission spectroscopy (AES), and atomic fluorescence spectroscopy (AFS). The first step in all three methods is atomization, where the solid, liquid, or solution-phase samples are converted into gas-phase atoms and...
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...
01:29Atomic Fluorescence Spectroscopy
Atomic fluorescence spectroscopy (AFS) is an analytical technique that involves the electronic transitions of atoms in a flame, furnace, or plasma being excited by electromagnetic (EM) radiation. When these atoms absorb energy, they become excited and subsequently release energy as they return to their original state. This emitted light, or "fluorescence," is observed at a right angle to the incident beam. Both absorption and emission processes transpire at distinct wavelengths, which are...
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,...
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...
04:01VSEPR Theory and the Effect of Lone Pairs
Effect of Lone Pairs of Electrons on Molecule Geometry