Abstract
The Paternò-Büchi (PB) reaction between an excited carbonyl compound and an alkene has been widely studied, but so far little is known about the excited-state dynamics of the reaction. In this investigation, we used a compound in which a formyl and a vinyl group are attached to a [2.2]paracyclophane in order to obtain a model system in pre-reactive conformation for the PB reaction. We studied the excited-state dynamics of the isolated molecule in a molecular beam using femtosecond time-resolved photoelectron spectroscopy and ab initio calculations. The results show that inter-system crossing within two picoseconds competes efficiently with the reaction in the singlet manifold. Thus, the PB reaction in this model system takes place in the triplet state on a time scale of nanoseconds. This result stresses the importance of triplet states in the excited-state pathway of the PB reaction involving aromatic carbonyl compounds, even in situations in which the reacting moieties are in immediate vicinity. This journal is
Originalsprog | Engelsk |
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Tidsskrift | Physical Chemistry Chemical Physics |
Vol/bind | 14 |
Udgave nummer | 24 |
Sider (fra-til) | 8572-8580 |
Antal sider | 9 |
ISSN | 1463-9076 |
DOI | |
Status | Udgivet - 28 jun. 2012 |