Photoelectron spectroscopy of anthracene and fluoranthene radical anions
- Univ. of Wisconsin, Madison, WI (United States). Dept. of Chemistry
Here, we report the slow electron velocity map imaging spectroscopy of cryogenically cooled anthracene and fluoranthene radical anions, two similarly sized polycyclic aromatic hydrocarbon molecules. The results allow us to examine the lowest energy singlet and triplet states in the neutral molecules on equal footing from the anionic ground state. The analysis of the experimental spectra is aided by harmonic calculations and Franck-Condon simulations, which generally show good agreement with experimental values and spectra. The electron affinity of fluoranthene is measured to be 0.757(2) eV, which is larger than that of anthracene at 0.532(3) eV. The lowest energy triplet state in anthracene is observed at 1.872(3) eV above the singlet ground state, while that of fluoranthene is observed at 2.321(2) eV above its singlet ground state. Comparisons of experimental and calculated spectra show that in addition to the Franck-Condon active modes, there is a clear presence of vibrational modes that gain intensity via vibronic coupling in both the singlet and triplet states in both molecules. In addition, the triplet state generally exhibits increased vibronic coupling compared to the singlet state, with the fluoranthene triplet state exhibiting evidence of distortion from C2v symmetry.
- Research Organization:
- Univ. of Wisconsin, Madison, WI (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES); National Science Foundation (NSF)
- Grant/Contract Number:
- SC0010326; CHE-0840494
- OSTI ID:
- 1469198
- Alternate ID(s):
- OSTI ID: 1456264
- Journal Information:
- Journal of Chemical Physics, Vol. 148, Issue 23; ISSN 0021-9606
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
High-resolution photoelectron imaging and resonant photoelectron spectroscopy via noncovalently bound excited states of cryogenically cooled anions
|
journal | January 2019 |
Vibrationally resolved photoelectron spectroscopy of oligothiophene radical anions
|
journal | October 2019 |
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