Ultrafast Dynamics of the Carbonyl Stretching Vibration in Acetic Acid in Aqueous Solution Studied by Sub-Picosecond Infrared Spectroscopy

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• 作者：Motohiro Banno ; Kaoru Ohta ; Keisuke Tominaga
• 刊名：Journal of Physical Chemistry A
• 出版年：2008
• 出版时间：May 8, 2008
• 年：2008
• 卷：112
• 期：18
• 页码：4170 - 4175
• 全文大小：202K
• 年卷期：v.112,no.18(May 8, 2008)
• ISSN：1520-5215

文摘

Vibrational energy relaxation of the carbonyl CO stretching modes of CH₃COOD and CD₃COOD in D₂O isstudied by frequency-resolved infrared pump-probe spectroscopy. The spectral change caused by the vibrationalexcitation includes two dynamical components with the time constants of 450 and 980 fs for CH₃COOD and390 and 930 fs for CD₃COOD. The two dynamical components exhibit different spectral properties. Thereare two species of acetic acid forming different complexes with solvent water molecules. The time constantsare almost the same for CH₃COOD and CD₃COOD, suggesting that the vibrational energy deposited to thecarbonyl group is first distributed among vibrational modes not related to the methyl group.