TY - JOUR
T1 - Ring-Opening Dynamics of the Cyclopropyl Radical and Cation
T2 - The Transition State Nature of the Cyclopropyl Cation
AU - Genossar, Nadav
AU - Changala, P. Bryan
AU - Gans, Bérenger
AU - Loison, Jean Christophe
AU - Hartweg, Sebastian
AU - Martin-Drumel, Marie Aline
AU - Garcia, Gustavo A.
AU - Stanton, John F.
AU - Ruscic, Branko
AU - Baraban, Joshua H.
N1 - Funding Information:
The authors are grateful to the SOLEIL general staff for providing synchrotron beamtime on the DESIRS beamline under proposal 20201007. This work has also received financial support from the French “Agence Nationale de la Recherche” (ANR) under grant no. ANR-12-BS08-0020-02 (project SYNCHROKIN). This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 848668). This work was also supported by the Israel Science Foundation (ISF), grant no. 194/20. The work at Argonne National Laboratory (B.R.) was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Chemical Sciences, Geosciences and Biosciences Division through the Gas-Phase Chemical Physics Program under grant number DE-AC02-06CH11357. We thank G. B. Ellison and K. B. Wiberg for bringing this fascinating system to our attention.
Publisher Copyright:
© 2022 American Chemical Society. All rights reserved.
PY - 2022/10/12
Y1 - 2022/10/12
N2 - We provide compelling experimental and theoretical evidence for the transition state nature of the cyclopropyl cation. Synchrotron photoionization spectroscopy employing coincidence techniques together with a novel simulation based on high-accuracy ab initio calculations reveal that the cation is unstable via its allowed disrotatory ring-opening path. The ring strains of the cation and the radical are similar, but both ring opening paths for the radical are forbidden when the full electronic symmetries are considered. These findings are discussed in light of the early predictions by Longuet-Higgins alongside Woodward and Hoffman; we also propose a simple phase space explanation for the appearance of the cyclopropyl photoionization spectrum. The results of this work allow the refinement of the cyclopropane C-H bond dissociation energy, in addition to the cyclopropyl radical and cation cyclization energies, via the Active Thermochemical Tables approach.
AB - We provide compelling experimental and theoretical evidence for the transition state nature of the cyclopropyl cation. Synchrotron photoionization spectroscopy employing coincidence techniques together with a novel simulation based on high-accuracy ab initio calculations reveal that the cation is unstable via its allowed disrotatory ring-opening path. The ring strains of the cation and the radical are similar, but both ring opening paths for the radical are forbidden when the full electronic symmetries are considered. These findings are discussed in light of the early predictions by Longuet-Higgins alongside Woodward and Hoffman; we also propose a simple phase space explanation for the appearance of the cyclopropyl photoionization spectrum. The results of this work allow the refinement of the cyclopropane C-H bond dissociation energy, in addition to the cyclopropyl radical and cation cyclization energies, via the Active Thermochemical Tables approach.
UR - http://www.scopus.com/inward/record.url?scp=85139451198&partnerID=8YFLogxK
U2 - 10.1021/jacs.2c07740
DO - 10.1021/jacs.2c07740
M3 - Article
C2 - 36174230
AN - SCOPUS:85139451198
SN - 0002-7863
VL - 144
SP - 18518
EP - 18525
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 40
ER -