title: Slow-to-fast transition of hydrogen bond dynamics in acetamide hydration shell formation.
abstract: The formation of a hydration shell in acetamide aqueous solution has been investigated by means of UV Raman spectroscopy. The experimental results reveal the existence of two distinct regimes of water dynamics. At high acetamide concentration water molecules show a structural and dynamical behavior consistent with the so-called iceberg model. Upon increasing the amount of water we observe the formation of a hydration shell marked by fastening of hydrogen-bond dynamics. Such a behavior may help to shed light on the scientific debate on how water rearranges around the hydrophobic portions of solute molecules (iceberg vs. non-iceberg models).
authors.affiliation: Elettra - Sincrotrone Trieste, Strada Statale 14 km 163.5, Area Science Park, I-34149 Trieste, Italy. francesco.damico@elettra.eu claudio.masciovecchio@elettra.eu.
authors.forename: Francesco
authors.initials: F
authors.lastname: D'Amico
authors.forename: Barbara
authors.initials: B
authors.lastname: Rossi
authors.forename: Gaia
authors.initials: G
authors.lastname: Camisasca
authors.forename: Filippo
authors.initials: F
authors.lastname: Bencivenga
authors.forename: Alessandro
authors.initials: A
authors.lastname: Gessini
authors.forename: Emiliano
authors.initials: E
authors.lastname: Principi
authors.forename: Riccardo
authors.initials: R
authors.lastname: Cucini
authors.forename: Claudio
authors.initials: C
authors.lastname: Masciovecchio
mesh_terms: D000081:Acetamides / Q000737:chemistry*; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D008958:Models, Molecular; D013059:Spectrum Analysis, Raman; D014867:Water / Q000737:chemistry*
chemical_list: D000081:Acetamides; D014867:Water; C030686:acetamide