Determination of the geometry change of the phenol dimer upon electronic excitation. |
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Authors: | Robert Brause Monika Santa Michael Schmitt Karl Kleinermanns |
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Institution: | Heinrich‐Heine‐Universit?t, Institut für Physikalische Chemie I, 40225 Düsseldorf, Germany, Fax: (+49)?211‐81‐15195 |
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Abstract: | The change of the phenol dimer (PH2) structure upon electronic excitation is determined by a Franck-Condon analysis of the intensities in the fluorescence emission spectra obtained via excitation of seven different vibronic bands. A total of 547 emission band intensities are fitted, together with the changes of rotational constants upon electronic excitation of fi ve isotopomers. These rotational constants are taken from previously published Schmitt et al. ChemPhysChem 2006, 7, 1241-1249] high-resolution LIF measurements. The geometry change upon electronic excitation of the pipi* state of the donor moiety can be described by a strong shortening of the hydrogen bond, a shortening of the CO bond in the donor moiety, an overall symmetric expansion of the donor phenol ring, and a nearly unchanged acceptor moiety. The resulting geometry changes are interpreted on the basis of ab initio calculations. |
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Keywords: | ab initio calculations fluorescence spectroscopy Franck–Condon analysis hydrogen bonds laser spectroscopy |
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