title: Temperature dependence of hydrogen-bond dynamics in acetic acid-water solutions.
abstract: An inelastic UV scattering experiment has been carried out on acetic acid-water solutions as a function of temperature and concentration. The analysis of experimental data indicates the presence of a crossover temperature (T(c) approximately 325 +/- 10 K). Above T(c), the energy of hydrogen bonds responsible for water-acetic acid and acetic acid-acetic acid interactions is strongly reduced. This leads to a reduction in the average number of water molecule interacting with acetic acid, as well as to a lower number of acetic acid clusters. The latter behavior can be mainly ascribed to a temperature change in the activation energy of carboxylic groups of acetic acid. These results may be also relevant to better understand the folding mechanism in protein-water solutions.
authors.affiliation: Sincrotrone Trieste, Strada Statale 14 km 163.5, Area Science Park, I-34149 Trieste, Italy. francesco.damico@elettra.trieste.it
authors.forename: Francesco
authors.initials: F
authors.lastname: D'Amico
authors.forename: Filippo
authors.initials: F
authors.lastname: Bencivenga
authors.forename: Alessandro
authors.initials: A
authors.lastname: Gessini
authors.forename: Claudio
authors.initials: C
authors.lastname: Masciovecchio
mesh_terms: D019342:Acetic Acid / Q000737:chemistry*; D006860:Hydrogen Bonding; D008956:Models, Chemical; D012996:Solutions / Q000737:chemistry*; D013016:Sound; D013696:Temperature; D014867:Water / Q000737:chemistry*
chemical_list: D012996:Solutions; D014867:Water; D019342:Acetic Acid