| Download | - View accepted manuscript: Pseudo-bimolecular [2+2] cycloaddition studied by time-resolved photoelectron spectroscopy (PDF, 890 KiB)
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| DOI | Resolve DOI: https://doi.org/10.1002/chem.201002928 |
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| Author | Search for: Brogaard, Rasmus Y.1; Search for: Boguslavskiy, Andrey E.1; Search for: Schalk, Oliver1; Search for: Enright, Gary D.1; Search for: Hopf, Henning; Search for: Raev, Vitaly A.; Search for: Jones, Peter G.; Search for: Thomsen, Ditte L.; Search for: Sølling, Theis I.; Search for: Stolow, Albert1 |
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| Affiliation | - National Research Council of Canada. NRC Steacie Institute for Molecular Sciences
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| Format | Text, Article |
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| Subject | ab initio calculations; cycloaddition; cyclophanes; photochemistry; photoelectron spectroscopy |
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| Abstract | 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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| Publication date | 2011-03-01 |
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| In | |
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| Language | English |
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| Peer reviewed | Yes |
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| NPARC number | 19739648 |
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| Export citation | Export as RIS |
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| Report a correction | Report a correction (opens in a new tab) |
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| Record identifier | 3c7d1236-3de3-4969-b8c8-379ce9ac221e |
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| Record created | 2012-04-02 |
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| Record modified | 2020-04-21 |
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