Ultrafast Laser-Induced Isomerization Dynamics in Acetonitrile.

Autor: McDonnell M; Department of Physics, University of Connecticut, Storrs, Connecticut 06269, United States., LaForge AC; Department of Physics, University of Connecticut, Storrs, Connecticut 06269, United States., Reino-González J; Departamento de Quı́mica, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid, Spain., Disla M; Department of Physics, University of Connecticut, Storrs, Connecticut 06269, United States., Kling NG; Department of Physics, University of Connecticut, Storrs, Connecticut 06269, United States., Mishra D; Department of Physics, University of Connecticut, Storrs, Connecticut 06269, United States., Obaid R; Department of Physics, University of Connecticut, Storrs, Connecticut 06269, United States., Sundberg M; Department of Physics, University of Connecticut, Storrs, Connecticut 06269, United States., Svoboda V; Laboratory of Physical Chemistry, ETH Zürich, 8093 Zürich, Switzerland., Díaz-Tendero S; Departamento de Quı́mica, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid, Spain.; Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain.; Institute for Advanced Research in Chemical Sciences(IAdChem), Universidad Autónoma de Madrid, 28049 Madrid, Spain., Martín F; Departamento de Quı́mica, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid, Spain.; Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain.; Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nano), Campus de Cantoblanco, 28049 Madrid, Spain.; Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, 20018 Donostia-San Sebastián, Spain., Berrah N; Department of Physics, University of Connecticut, Storrs, Connecticut 06269, United States.
Jazyk: angličtina
Zdroj: The journal of physical chemistry letters [J Phys Chem Lett] 2020 Aug 20; Vol. 11 (16), pp. 6724-6729. Date of Electronic Publication: 2020 Aug 06.
DOI: 10.1021/acs.jpclett.0c01344
Abstrakt: Isomerization induced by laser ionization in acetonitrile (CH 3 CN) was investigated using pump-probe spectroscopy in combination with ion-ion coincident Coulomb explosion imaging. We deduced five primary channels indicating direct C-C breakup, single and double hydrogen migration, and H and H 2 dissociation in the acetonitrile cation. Surprisingly, the hydrogen-migration channels dominate over direct fragmentation. This observation is supported by quantum chemistry calculations showing that isomerization through single and double hydrogen migration leads to very stable linear and ring isomers, with most of them more stable than the original linear structure following ionization of the parent molecule. This is unlike most molecules investigated previously using similar schemes. By varying the delay between the pump and probe pulses, we have also determined the time scales of the corresponding dynamical processes. Isomerization typically occurs in a few hundred femtoseconds, a time scale that is comparable to that found for H and H 2 dissociation and direct molecular fragmentation.
Databáze: MEDLINE
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