Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Negative Ion Photoelectron Spectroscopy Confirms the Prediction of a Singlet Ground State for the 1,8-Naphthoquinone Diradical

Journal Article · · Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory
Negative ion photoelectron (NIPE) spectra, with 193, 266, 300, and 355 nm photons, of the radical anion of 1,8-naphthoquinone (1,8-NQ•-) have been obtained at 20K. The electron affinity of 1,8-NQ is determined from the first resolved peak in the NIPE spectrum to be 2.98 ± 0.04 eV. Franck-Condon factors (FCFs), calculated from the CASPT2/aug-cc-pVDZ optimized geometries, normal modes, and vibrational frequencies successfully simulate the intensity and frequencies of the spectral features that are associated with the lowest two electronic states. Here, the NIPE spectra of 1,8-NQ•- and the peak assignments, based on the computed FCFs, confirm the theoretical predictions that 1A1 is the ground state of 1,8- NQ and that 3B2 is the first excited state. The spectra provide an experimental value of ΔEST = -1.5 kcal/mol, which is within about 1 kcal/mol of the (12/12)CASPT2/aug-cc-pVTZ calculated value of ΔEST = -2.6 kcal/mol.
Research Organization:
Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
Sponsoring Organization:
USDOE
Grant/Contract Number:
AC05-76RL01830
OSTI ID:
1530598
Report Number(s):
PNNL-SA--139614
Journal Information:
Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory, Journal Name: Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory Journal Issue: 14 Vol. 123; ISSN 1089-5639
Publisher:
American Chemical SocietyCopyright Statement
Country of Publication:
United States
Language:
English

Similar Records

Calculations on 1,8-naphthoquinone predict that the ground state of this diradical is a singlet: Calculations on 1,8-Naphthoquinone Predict that the Ground State of this Diradical Is a Singlet
Journal Article · Wed Oct 03 00:00:00 EDT 2018 · Journal of Computational Chemistry · OSTI ID:1489226

Negative Ion Photoelectron Spectroscopy Confirms the Prediction of the Relative Energies of the Low-Lying Electronic States of 2,7-Naphthoquinone
Journal Article · Thu May 31 00:00:00 EDT 2018 · Journal of Physical Chemistry A · OSTI ID:1781319

The Negative Ion Photoelectron Spectrum of meta -Benzoquinone Radical Anion (MBQ •– ): A Joint Experimental and Computational Study
Journal Article · Tue Mar 04 23:00:00 EST 2014 · Journal of the American Chemical Society · OSTI ID:1129288