On the Inoperativeness of the ESIPT Process in the Emission of 1-Hydroxy-2-acetonaphthone: A Reappraisal
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- 作者：J. Catalá ; n ; J. L. G. de Paz
- 刊名：Journal of Physical Chemistry A
- 出版年：2008
- 出版时间：February 7, 2008
- 年：2008
- 卷：112
- 期：5
- 页码：904 - 914
- 全文大小：348K
- 年卷期：v.112,no.5(February 7, 2008)
- ISSN：1520-5215
文摘
For a molecule which contains an intramolecular hydrogen bond (IMHB) in its chemical structure to undergoan excited singlet intramolecular proton transfer (ESIPT) process, on photoexcitation, there must occur asimultaneous increase, in a substantial manner, in the acidity of the proton donor and the basicity of theproton acceptor forming the IMHB [J. Am. Chem. Soc. 2001, 123, 11940]. For the reason that those changesoccur on photoexcitation of the 2-hydroxyacetophenone but not for 1-hydroxy-acetonaphthone, one drawsthe conclusion that, while ESIPT is operative in the 1(
,*)1 electronic state of the monocyclic compound2-hydroxyacetophenone, it is not operative in its bicyclic homolog 1-hydroxy-2-acetonaphthone. We haveshown the photophysics of 1-hydroxy-2-acetonaphthone in its first excited electronic state to be governed bytwo stable, easily reconverted enol structures, the presence of which causes the peaks in the free-jet fluorescenceexcitation spectrum for the compound to split into two of similar strength. In this paper, we rationalizephotophysical evidence for 1-hydroxy-2-acetonaphthone obtained by femtosecond spectroscopy over the past13 years in the light of existing photophysical patterns based on steady-state spectra for the compound [J.Am. Chem. Soc. 1993, 115, 4321].
,*)1 electronic state of the monocyclic compound2-hydroxyacetophenone, it is not operative in its bicyclic homolog 1-hydroxy-2-acetonaphthone. We haveshown the photophysics of 1-hydroxy-2-acetonaphthone in its first excited electronic state to be governed bytwo stable, easily reconverted enol structures, the presence of which causes the peaks in the free-jet fluorescenceexcitation spectrum for the compound to split into two of similar strength. In this paper, we rationalizephotophysical evidence for 1-hydroxy-2-acetonaphthone obtained by femtosecond spectroscopy over the past13 years in the light of existing photophysical patterns based on steady-state spectra for the compound [J.Am. Chem. Soc. 1993, 115, 4321].