Abstract A unique approach is used to relate the HOMO‐LUMO energy difference to the difference between the ionization potential (IP) and electron affinity (EA) to assist in deducing not only the colors, but also chromophores in elemental nonmetals. Our analysis focuses on compounds with lone pair electrons and σ electrons, namely X2(X = F, Cl, Br, I), S8and P4. For the dihalogens, the [IP – EA] energies are found to be: F2(12.58 eV), Cl2(8.98 eV), Br2(7.90 eV), I2(6.78 eV). We suggest that theinterahalogen X–X bond itself is the chromophore for these dihalogens, in which the light absorbed by the F2, Cl2, Br2, I2leads to longer wavelengths in the visible by a π → σ* transition. Trace impurities are a likely case of cyclic S8which contains amounts of selenium leading to a yellow color, where the [IP – EA] energy of S8is found to be 7.02 eV. Elemental P4with an [IP – EA] energy of 9.09 eV contains a tetrahedral and σ aromatic structure. In future work, refinement of the analysis will be required for compounds with π electrons and σ electrons, such as polycyclic aromatic hydrocarbons (PAHs).
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The kinetic energy of PAH dication and trication dissociation determined by recoil-frame covariance map imaging
We investigated the dissociation of dications and trications of three polycyclic aromatic hydrocarbons (PAHs), fluorene, phenanthrene, and pyrene. PAHs are a family of molecules ubiquitous in space and involved in much of the chemistry of the interstellar medium. In our experiments, ions are formed by interaction with 30.3 nm extreme ultraviolet (XUV) photons, and their velocity map images are recorded using a PImMS2 multi-mass imaging sensor. Application of recoil-frame covariance analysis allows the total kinetic energy release (TKER) associated with multiple fragmentation channels to be determined to high precision, ranging 1.94–2.60 eV and 2.95–5.29 eV for the dications and trications, respectively. Experimental measurements are supported by Born–Oppenheimer molecular dynamics (BOMD) simulations.
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- Award ID(s):
- 1753324
- PAR ID:
- 10438831
- Author(s) / Creator(s):
- ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »
- Date Published:
- Journal Name:
- Physical Chemistry Chemical Physics
- Volume:
- 24
- Issue:
- 38
- ISSN:
- 1463-9076
- Page Range / eLocation ID:
- 23096 to 23105
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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