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Title: Revealing electronic state-switching at conical intersections in alkyl iodides by ultrafast XUV transient absorption spectroscopy

Abstract

Conical intersections between electronic states often dictate the chemistry of photoexcited molecules. Recently developed sources of ultrashort extreme ultraviolet (XUV) pulses tuned to element-specific transitions in molecules allow for the unambiguous detection of electronic state-switching at a conical intersection. Here, the fragmentation of photoexcited iso-propyl iodide and tert-butyl iodide molecules (i-C3H7I and t-C4H9I) through a conical intersection between 3Q0/1Q1 spin-orbit states is revealed by ultrafast XUV transient absorption measuring iodine 4d core-to-valence transitions. The electronic state-sensitivity of the technique allows for a complete mapping of molecular dissociation from photoexcitation to photoproducts. In both molecules, the sub-100 fs transfer of a photoexcited wave packet from the 3Q0 state into the 1Q1 state at the conical intersection is captured. The results show how differences in the electronic state-switching of the wave packet in i-C3H7I and t-C4H9I directly lead to differences in the photoproduct branching ratio of the two systems.

Authors:
ORCiD logo [1];  [1]; ORCiD logo [2]; ORCiD logo [3]; ORCiD logo [1];  [4]; ORCiD logo [5]; ORCiD logo [4]; ORCiD logo [4]
  1. Univ. of California, Berkeley, CA (United States)
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  3. Univ. of California, Berkeley, CA (United States); Univ. Complutense de Madrid (Spain)
  4. Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  5. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Molecular Foundry
Publication Date:
Research Org.:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES); National Science Foundation (NSF); US Army Research Office (ARO)
OSTI Identifier:
1650126
Grant/Contract Number:  
AC02-05CH11231; CHE-1660417; CHE-1361226; W911NF-14-1-0383
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Nature Communications
Additional Journal Information:
Journal Volume: 11; Journal Issue: 1; Journal ID: ISSN 2041-1723
Publisher:
Nature Publishing Group
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Chemistry; physics

Citation Formats

Chang, Kristina F., Reduzzi, Maurizio, Wang, Han, Poullain, Sonia M., Kobayashi, Yuki, Barreau, Lou, Prendergast, David, Neumark, Daniel M., and Leone, Stephen R. Revealing electronic state-switching at conical intersections in alkyl iodides by ultrafast XUV transient absorption spectroscopy. United States: N. p., 2020. Web. doi:10.1038/s41467-020-17745-w.
Chang, Kristina F., Reduzzi, Maurizio, Wang, Han, Poullain, Sonia M., Kobayashi, Yuki, Barreau, Lou, Prendergast, David, Neumark, Daniel M., & Leone, Stephen R. Revealing electronic state-switching at conical intersections in alkyl iodides by ultrafast XUV transient absorption spectroscopy. United States. https://doi.org/10.1038/s41467-020-17745-w
Chang, Kristina F., Reduzzi, Maurizio, Wang, Han, Poullain, Sonia M., Kobayashi, Yuki, Barreau, Lou, Prendergast, David, Neumark, Daniel M., and Leone, Stephen R. 2020. "Revealing electronic state-switching at conical intersections in alkyl iodides by ultrafast XUV transient absorption spectroscopy". United States. https://doi.org/10.1038/s41467-020-17745-w. https://www.osti.gov/servlets/purl/1650126.
@article{osti_1650126,
title = {Revealing electronic state-switching at conical intersections in alkyl iodides by ultrafast XUV transient absorption spectroscopy},
author = {Chang, Kristina F. and Reduzzi, Maurizio and Wang, Han and Poullain, Sonia M. and Kobayashi, Yuki and Barreau, Lou and Prendergast, David and Neumark, Daniel M. and Leone, Stephen R.},
abstractNote = {Conical intersections between electronic states often dictate the chemistry of photoexcited molecules. Recently developed sources of ultrashort extreme ultraviolet (XUV) pulses tuned to element-specific transitions in molecules allow for the unambiguous detection of electronic state-switching at a conical intersection. Here, the fragmentation of photoexcited iso-propyl iodide and tert-butyl iodide molecules (i-C3H7I and t-C4H9I) through a conical intersection between 3Q0/1Q1 spin-orbit states is revealed by ultrafast XUV transient absorption measuring iodine 4d core-to-valence transitions. The electronic state-sensitivity of the technique allows for a complete mapping of molecular dissociation from photoexcitation to photoproducts. In both molecules, the sub-100 fs transfer of a photoexcited wave packet from the 3Q0 state into the 1Q1 state at the conical intersection is captured. The results show how differences in the electronic state-switching of the wave packet in i-C3H7I and t-C4H9I directly lead to differences in the photoproduct branching ratio of the two systems.},
doi = {10.1038/s41467-020-17745-w},
url = {https://www.osti.gov/biblio/1650126}, journal = {Nature Communications},
issn = {2041-1723},
number = 1,
volume = 11,
place = {United States},
year = {Wed Aug 12 00:00:00 EDT 2020},
month = {Wed Aug 12 00:00:00 EDT 2020}
}

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