ESIPT proton-transfer

Lukeman, M. Veale, D. Wan, R Munasinghe, V. R. N. Corrie, J. E. T. Photogeneration of 1,5-naphthoquinone methides via excited-state (formal) intramolecular proton transfer (ESIPT) and photodehydration of 1-naphthol derivatives in aqueous solution. Can. J. Chem. 2004, 82, 240-253. 

Le Gourrierec, D. Ormson, S. M. Brown, R. G. Excited-state intramolecular proton transfer. Part 2 ESIPT to oxygen. Prog. React. Kinet. 1994, 19, 211-275. 

Brousmiche, D. W. Wan, P. Excited state (formal) intramolecular proton transfer (ESIPT) in p-hydroxyphenyl ketones mediated hy water. J. Photochem. Photobiol. A Chem. 2000, 130, 113-118. 

Lukeman, M. Wan, P. Excited state intramolecular proton transfer (ESIPT) in 2-phenylphenol an example of proton transfer to a carbon of an aromatic ring. J. Chem. Soc., Chem. Commun. 2001, 1004-1005. 

Excited-state intramolecular proton transfer (ESIPT) exhibits different regularities [49, 50]. Commonly, this is a very fast and practically irreversible reaction proceeding along the H-bonds preexisting in the ground state. Therefore, only the reaction product band is seen in fluorescence spectra. Such cases are not interesting for designing the fluorescence reporters. The more attractive dual emission is... 

The fundamental approach to a proton transfer process, which is crucial to mimic many chemical and biological reactions, has relied deeply on studies of excited-state intramolecular proton transfer (ESIPT) reactions in the condensed phase. 

Seminal studies on the dynamics of proton transfer in the triplet manifold have been performed on HBO [109]. It was found that in the triplet states of HBO, the proton transfer between the enol and keto tautomers is reversible because the two (enol and keto) triplet states are accidentally isoenergetic. In addition, the rate constant is as slow as milliseconds at 100 K. The results of much slower proton transfer dynamics in the triplet manifold are consistent with the earlier summarization of ESIPT molecules. Based on the steady-state absorption and emission spectroscopy, the changes of pKa between the ground and excited states, and hence the thermodynamics of ESIPT, can be deduced by a Forster cycle [65]. Accordingly, compared to the pKa in the ground state, the decrease of pKa in the... 

Fig. 16 A generalized ESCT/ ESIPT system and its possible reaction patterns. ( denotes the electronically excited state, PT and CT symbolize proton transfer and charge transfer species, respectively) (reprint from ref. [145], Copyright 2008 American Chemical Society)...

Lim SJ, Seo J, Park SY (2006) Photochromic switching of excited-state intramolecular proton-transfer (ESIPT) fluorescence a unique route to high-contrast memory switching and nondestructive readout. J Am Chem Soc 128 14542-14547... 

Ameer-Beg S, Ormson SM, Brown RG et al (2001) Ultrafast measurements of excited state intramolecular proton transfer (ESIPT) in room temperature solutions of 3-hydroxyflavone and derivatives. J Phys Chem A 105 3709-3718... 

Fig. 4 Excited state intramolecular proton-transfer (ESIPT) mechanism of 3-hydroxychromone...

To conclude our description of techniques, the use of nanosecond and picosecond spectroscopy which has been applied to excited state intramolecular proton transfer (ESIPT) will be mentioned briefly (Beens et al., 1965 Huppert et al., 1981 Hilinski and Rentzepis, 1983). A large number of inter-and intramolecular proton transfers have been studied using these methods (Ireland and Wyatt, 1976) but in the case of processes which are thought to involve simple proton transfer along an intramolecular hydrogen bond it is usually only possible to estimate a lower limit for the rate coefficient. 

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