Abstract
We report an observation of spin-orbit excited dipole-bound states (DBSs) in arginine-iodide complexes (Arg·I-) by using temperature-dependent, wavelength-resolved "iodide-tagging"negative ion photoelectron spectroscopy. The observed DBSs are bound to the spin-orbit excited I(2P1/2) level of the neutral Arg·I complex in zwitterionic conformations and identified based on the resonant enhancement due to spin-orbit electronic autodetachment from the I(2P1/2) DBS to the I(2P3/2) neutral ground state. The observed DBS binding energies are correlated to the dipole moments of neutral Arg·I isomers and tautomers. This work thus demonstrates a new and generic spectroscopic approach to identify ion-molecule cluster conformations based on their distinguishable dipole moments.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 11022-11028 |
| Number of pages | 7 |
| Journal | Journal of Physical Chemistry Letters |
| Volume | 12 |
| Issue number | 45 |
| DOIs | |
| State | Published - Nov 18 2021 |
Bibliographical note
Funding Information:The work was supported by U.S. Department of Energy (DOE), Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences, and performed using EMSL, a national scientific user facility sponsored by DOE’s Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory, which is operated by Battelle Memorial Institute for the DOE. The theoretical calculations were conducted on the EMSL Cascade Supercomputer and at the University of Minnesota Supercomputing Institute. S.R.K. acknowledges support from the National Science Foundation (CHE-1955186). X.Z. appreciates the financial support of the National Natural Science Foundation of China (No. 21873089).
Publisher Copyright:
© 2021 American Chemical Society.