title: Excited-state proton transfer of 3-hydroxybenzoic acid and 4-hydroxybenzoic acid.
abstract: The excited-state proton transfer of 3-hydroxybenzoic acid and 4-hydroxybenzoic acid was studied by time-resolved laser-induced fluorescence spectroscopy with ultra-short laser pulses. The excited-state reactions were identified in aqueous media as a function of the pH value. Apart from the well-known inversion of the ordinary dissociation properties of these compounds, new species were found which exist only in the excited-state resulting from a temporal and reversible annihilation of the aromatic bond system. These species and their reaction mechanisms were detected by their absorption and fluorescence spectra.
authors.affiliation: Forschungszentrum Dresden-Rossendorf e V, Institute of Radiochemistry, PO Box 510119, 01314 Dresden, Germany. d.vulpius@fzd.de
authors.forename: D
authors.initials: D
authors.lastname: Vulpius
authors.forename: G
authors.initials: G
authors.lastname: Geipel
authors.forename: G
authors.initials: G
authors.lastname: Bernhard
mesh_terms: D062385:Hydroxybenzoates / Q000737:chemistry*; D010226:Parabens / Q000737:chemistry*; D011522:Protons; D013050:Spectrometry, Fluorescence
chemical_list: D062385:Hydroxybenzoates; D010226:Parabens; D011522:Protons; C032948:3-hydroxybenzoic acid; C038193:4-hydroxybenzoic acid