dc.creator Wörner, Hans Jakob en_US dc.creator Merkt, F. en_US dc.date.accessioned 2008-01-11T21:36:48Z dc.date.available 2008-01-11T21:36:48Z dc.date.issued 2005 en_US dc.identifier 2005-FD-07 en_US dc.identifier.uri http://hdl.handle.net/1811/30287 dc.description rule a. S. Willitsch, J.M. Dyke and F. Merkt, Helv. Chim. Acta, {\bf 86 en_US dc.description Author Institution: PHYSIKALISCHE CHEMIE, ETH ZURICH, CH-8093 ZURICH en_US dc.description.abstract This presentation summarizes the results of the first photoelectron spectroscopic study of the cyclopentadienyl radical. The cyclopentadienyl radical was produced in a supersonic expansion by photolysis of cyclopentadiene at 248 nm using the method described in Ref. a. PFI-ZEKE photoelectron spectra were recorded using two different excitation schemes. In the first experiment single-photon excitation from the $\tilde{X}$ $^2$E$_1''$ ground state of the radical was used to study the ground state of the cyclopentadienyl cation. In the second experiment, a resonance-enhanced two-photon excitation scheme via the vibrationless transition to the $\tilde{A}$ $^2$A$_2''$ studied in Ref. b provided access to the first electronically excited state of the cyclopentadienyl cation. The analysis of the spectra reveals that the ground state of the cyclopentadienyl cation is a triplet state of electronic symmetry $^3$A$_2'$ and the first excited state is a singlet of symmetry $^1$E$_2'$, which is subject to a pronounced Jahn-Teller distortion. The results of {\it ab initio} calculations together with a preliminary analysis of the Jahn-Teller effect in the $^1$E$_2'$ state are presented. \\ }, 1152 (2003).\\ b. L. Yu, S.C. Foster, J.M. Williamson, M.C. Heaven and T.A. Miller, J. Chem. Phys. {\bf 92}, 4263 (1988). en_US dc.language.iso English en_US dc.publisher Ohio State University en_US dc.title HIGH-RESOLUTION PFI-ZEKE PHOTOELECTRON SPECTROSCOPY OF THE CYCLOPENTADIENYL RADICAL en_US dc.type article en_US
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