Temperature dependence of hydrogen-bond dynamics in acetic acid-water solutions.
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.
D'Amico
Francesco
F
Sincrotrone Trieste, Strada Statale 14 km 163.5, Area Science Park, I-34149 Trieste, Italy. francesco.damico@elettra.trieste.it
Bencivenga
Filippo
F
Gessini
Alessandro
A
Masciovecchio
Claudio
C
D019342:Acetic Acid / Q000737:chemistry*; D006860:Hydrogen Bonding; D008956:Models, Chemical; D012996:Solutions / Q000737:chemistry*; D013016:Sound; D013696:Temperature; D014867:Water / Q000737:chemistry*
D012996:Solutions; D014867:Water; D019342:Acetic Acid