title: Unexpected Ultrafast Silver Ion Reduction: Dynamics Driven by the Solvent Structure.
abstract: Picosecond pulse radiolysis measurements have been performed in neutral and highly acidic aqueous solutions containing silver ions at different concentrations. Silver ion reduction is used to understand the ultrafast chemistry of irradiated water and aqueous solutions. The absorption band measured at the end of the 7-ps electron pulses has an intense band with a maximum at 360 nm due to the formation of silver atoms. Kinetics shows that the amount of silver atom formed at the end of the electron pulse in phosphoric acid solutions is greater than that in neutral water. This unexpectedly high yield of silver atom formation cannot be explained solely by the reaction between silver ions and solvated electrons in neutral solutions nor by the reaction with hydrogen atoms in phosphoric acid solutions. To explain the observed ultrafast reduction of silver ions, the presolvated electron, be it free or paired to the hydronium cation, must react very quickly with a silver ion, potentially competing with geminate recombination of the electron and its sibling radical cation.
authors.affiliation: †Laboratoire de Chimie Physique, CNRS/Université Paris-Sud, Bâtiment 349, 91405 Orsay, France.
authors.forename: Anna
authors.initials: A
authors.lastname: Balcerzyk
authors.affiliation: †Laboratoire de Chimie Physique, CNRS/Université Paris-Sud, Bâtiment 349, 91405 Orsay, France.
authors.forename: Uli
authors.initials: U
authors.lastname: Schmidhammer
authors.affiliation: †Laboratoire de Chimie Physique, CNRS/Université Paris-Sud, Bâtiment 349, 91405 Orsay, France.|‡Dalton Cumbrian Facility, The University of Manchester, Westlakes Science and Technology Park, Moor Row, Cumbria, CA24 3HA, United Kingdom.|§School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom.
authors.forename: Gregory
authors.initials: G
authors.lastname: Horne
authors.affiliation: †Laboratoire de Chimie Physique, CNRS/Université Paris-Sud, Bâtiment 349, 91405 Orsay, France.
authors.forename: Furong
authors.initials: F
authors.lastname: Wang
authors.affiliation: †Laboratoire de Chimie Physique, CNRS/Université Paris-Sud, Bâtiment 349, 91405 Orsay, France.
authors.forename: Jun
authors.initials: J
authors.lastname: Ma
authors.affiliation: ‡Dalton Cumbrian Facility, The University of Manchester, Westlakes Science and Technology Park, Moor Row, Cumbria, CA24 3HA, United Kingdom.|§School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom.
authors.forename: Simon M
authors.initials: SM
authors.lastname: Pimblott
authors.affiliation: †Laboratoire de Chimie Physique, CNRS/Université Paris-Sud, Bâtiment 349, 91405 Orsay, France.
authors.forename: Aurélien
authors.initials: A
authors.lastname: de la Lande
authors.affiliation: †Laboratoire de Chimie Physique, CNRS/Université Paris-Sud, Bâtiment 349, 91405 Orsay, France.
authors.forename: Mehran
authors.initials: M
authors.lastname: Mostafavi