| Téléchargement | - Voir le manuscrit accepté : Pseudo-bimolecular [2+2] cycloaddition studied by time-resolved photoelectron spectroscopy (PDF, 890 Kio)
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| DOI | Trouver le DOI : https://doi.org/10.1002/chem.201002928 |
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| Auteur | Rechercher : Brogaard, Rasmus Y.1; Rechercher : Boguslavskiy, Andrey E.1; Rechercher : Schalk, Oliver1; Rechercher : Enright, Gary D.1; Rechercher : Hopf, Henning; Rechercher : Raev, Vitaly A.; Rechercher : Jones, Peter G.; Rechercher : Thomsen, Ditte L.; Rechercher : Sølling, Theis I.; Rechercher : Stolow, Albert1 |
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| Affiliation | - Conseil national de recherches du Canada. Institut Steacie des sciences moléculaires du CNRC
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| Format | Texte, Article |
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| Sujet | ab initio calculations; cycloaddition; cyclophanes; photochemistry; photoelectron spectroscopy |
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| Résumé | The first study of pseudo-bimolecular cycloaddition reaction dynamics in the gas phase is presented. We used femtosecond time-resolved photoelectron spectroscopy (TRPES) to study the [2+2] photocycloaddition in the model system pseudo-gem-divinyl[2.2]paracyclophane. From X-ray crystal diffraction measurements we found that the ground-state molecule can exist in two conformers; a reactive one in which the vinyl groups are immediately situated for [2+2] cycloaddition and a nonreactive conformer in which they point in opposite directions. From the measured S1 lifetimes we assigned a clear relation between the conformation and the excited-state reactivity; the reactive conformer has a lifetime of 13 ps, populating the ground state through a conical intersection leading to [2+2] cycloaddition, whereas the nonreactive conformer has a lifetime of 400 ps. Ab initio calculations were performed to locate the relevant conical intersection (CI) and calculate an excited-state [2+2] cycloaddition reaction path. The interpretation of the results is supported by experimental results on the similar but nonreactive pseudo-para-divinyl[2.2]paracyclophane, which has a lifetime of more than 500 ps in the S1 state. |
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| Date de publication | 2011-03-01 |
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| Dans | |
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| Langue | anglais |
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| Publications évaluées par des pairs | Oui |
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| Numéro NPARC | 19739648 |
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| Exporter la notice | Exporter en format RIS |
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| Signaler une correction | Signaler une correction (s'ouvre dans un nouvel onglet) |
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| Identificateur de l’enregistrement | 3c7d1236-3de3-4969-b8c8-379ce9ac221e |
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| Enregistrement créé | 2012-04-02 |
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| Enregistrement modifié | 2020-04-21 |
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