Article ID Journal Published Year Pages File Type
5375910 Chemical Physics 2008 10 Pages PDF
Abstract
The photochemistry of the fluorescent Pigment Yellow 101 (P.Y.101) in the crystalline phase is investigated combining time resolved vibrational and electronic spectroscopy. The experiments reveal a complex reaction dynamics spanning several orders of magnitude in time and including excited state intramolecular proton transfer (ESIPT) from the initial trans-diol conformer. Following photoexcitation and the subsequent wavepacket motion out of the Franck-Condon region two tautomers, an excited trans-diol and trans-keto state are formed. The cis-trans isomerization of the keto form, which was experimentally observed and theoretically confirmed in DFT calculations in studies on P.Y.101 in solution is obstructed in the solid state, consequently the formation of the cis conformer is not directly observed. In addition, a long lived photoproduct with red shifted vibrational frequencies is identified. The life time of this intermediate is determined to be 50 μs, although an unambiguous assignment to a specific molecular configuration cannot be given at present.
Related Topics
Physical Sciences and Engineering Chemistry Physical and Theoretical Chemistry
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