Temperature Dependence of Hydrogen-Bond Dynamics in Acetic Acid−Water Solutions

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• 作者：Francesco D’ ; Amico ; Filippo Bencivenga ; Alessandro Gessini ; Claudio Masciovecchio
• 刊名：Journal of Physical Chemistry B
• 出版年：2010
• 出版时间：August 19, 2010
• 年：2010
• 卷：114
• 期：32
• 页码：10628-10633
• 全文大小：260K
• 年卷期：v.114,no.32(August 19, 2010)
• ISSN：1520-5207

文摘

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 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.