title: Photoacid for extremely long-lived and reversible pH-jumps.
abstract: The ability to change the acidity of an aqueous solution within the time of a short laser pulse and use the resulting low pH to drive acid-catalyzed reactions in the irradiated volume opens news perspectives for the spatial and temporal control of a variety of processes. Persistent and reversible acidification of an aqueous solution is achieved with a new molecule, 1-(2-nitroethyl)-2-naphthol, that combines the fast photoacid properties of an aromatic alcohol with the slow proton transfer rates of a nitroalkane. The protons released in a few nanoseconds by pulsed laser excitation of the photoacid last for nearly one second in aqueous solutions. We show that acid-base equilibria with other species is established at the lower pHs of the irradiated volume, that the process is reversible and that it can be maintained under continuous irradiation.
authors.affiliation: Chemistry Department, University of Coimbra, 3000 Coimbra, Portugal.
authors.forename: Rui M D
authors.initials: RM
authors.lastname: Nunes
authors.forename: Marta
authors.initials: M
authors.lastname: Pineiro
authors.forename: Luis G
authors.initials: LG
authors.lastname: Arnaut