title: Delayed Onset of Crystallinity in Ion-Containing Aqueous Nanodrops.
abstract: Water exhibits remarkable properties in confined spaces, such as nanometer-sized droplets where hundreds of water molecules are required for crystalline structure to form at low temperature due to surface effects. Here, we investigate how a single ion affects the crystallization of (H2O)n clusters with infrared photodissociation spectroscopy of size-selected La(3+)(H2O)n nanodrops containing up to 550 water molecules. Crystallization in the ion-containing nanodrops occurs at n ≥ 375, which is approximately 100 more water molecules than what has been reported for neutral water clusters. This frustration of crystallinity reveals that La(3+) disrupts the hydrogen-bonding network of water molecules located remotely from the ion, a conclusion that is supported by molecular dynamics simulations. Our findings establish that a trivalent ion can pattern the H-bond network of water molecules beyond the third solvation shell, or to a distance of ∼1 nm from the ion.
authors.affiliation: Department of Chemistry, University of California , Berkeley, California 94720-1460, United States.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Cooper
authors.affiliation: Department of Chemistry, University of California , Berkeley, California 94720-1460, United States.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: DiTucci
authors.affiliation: Department of Chemistry, University of California , Berkeley, California 94720-1460, United States.
authors.forename: Terrence M
authors.initials: TM
authors.lastname: Chang
authors.affiliation: Department of Chemistry, University of California , Berkeley, California 94720-1460, United States.
authors.forename: Evan R
authors.initials: ER
authors.lastname: Williams