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Marcellini M, Nasedkin A, Zietz B, Petersson J, Vincent J, Palazzetti F, Malmerberg E, Kong Q, Wulff M, van der Spoel D, Neutze R, Davidsson J. Transient isomers in the photodissociation of bromoiodomethane. J Chem Phys 2018; 148:134307. [PMID: 29626862 DOI: 10.1063/1.5005595] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The photochemistry of halomethanes is fascinating for the complex cascade reactions toward either the parent or newly synthesized molecules. Here, we address the structural rearrangement of photodissociated CH2IBr in methanol and cyclohexane, probed by time-resolved X-ray scattering in liquid solution. Upon selective laser cleavage of the C-I bond, we follow the reaction cascade of the two geminate geometrical isomers, CH2I-Br and CH2Br-I. Both meta-stable isomers decay on different time scales, mediated by solvent interaction, toward the original parent molecule. We observe the internal rearrangement of CH2Br-I to CH2I-Br in cyclohexane by extending the time window up to 3 μs. We track the photoproduct kinetics of CH2Br-I in methanol solution where only one isomer is observed. The effect of the polarity of solvent on the geminate recombination pathways is discussed.
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Affiliation(s)
- Moreno Marcellini
- Department of Chemistry-Ångström Laboratory, Uppsala University, P.O. Box 462, SE-751 20 Uppsala, Sweden
| | - Alexandr Nasedkin
- Department of Chemistry-Ångström Laboratory, Uppsala University, P.O. Box 462, SE-751 20 Uppsala, Sweden
| | - Burkhard Zietz
- Department of Chemistry-Ångström Laboratory, Uppsala University, P.O. Box 462, SE-751 20 Uppsala, Sweden
| | - Jonas Petersson
- Department of Chemistry-Ångström Laboratory, Uppsala University, P.O. Box 462, SE-751 20 Uppsala, Sweden
| | - Jonathan Vincent
- Department of Chemistry-Ångström Laboratory, Uppsala University, P.O. Box 462, SE-751 20 Uppsala, Sweden
| | - Federico Palazzetti
- Universitá di Perugia, Dipartimento di Chimica, Biologia e Biotecnologie, 06123 Perugia, Italy
| | - Erik Malmerberg
- Department of Chemistry and Molecular Biology, University of Gothenburg, SE-405 30 Gothenburg, Sweden
| | - Qingyu Kong
- Argonne National Laboratory's, Xray Science Division, 9700 S Cass Ave., Argonne, Illinois 60439, USA
| | - Michael Wulff
- European Synchrotron Radiation Facility, B.P. 220, F-380 43 Grenoble Cedex, France
| | - David van der Spoel
- Department of Cell and Molecular Biology, Uppsala University, Husargatan 3, P.O. Box 596, SE-751 24 Uppsala, Sweden
| | - Richard Neutze
- Department of Chemistry and Molecular Biology, University of Gothenburg, SE-405 30 Gothenburg, Sweden
| | - Jan Davidsson
- Department of Chemistry-Ångström Laboratory, Uppsala University, P.O. Box 462, SE-751 20 Uppsala, Sweden
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