Banno Motohiro, Ohta Kaoru, Tominaga Keisuke
Molecular Photoscience Research Center, Kobe University, Graduate School of Science and Technology, Kobe University, Kobe 657-8501, Japan.
J Phys Chem A. 2008 May 8;112(18):4170-5. doi: 10.1021/jp076920m. Epub 2008 Mar 29.
Vibrational energy relaxation of the carbonyl CO stretching modes of CH3COOD and CD3COOD in D2O is studied by frequency-resolved infrared pump-probe spectroscopy. The spectral change caused by the vibrational excitation includes two dynamical components with the time constants of 450 and 980 fs for CH3COOD and 390 and 930 fs for CD3COOD. The two dynamical components exhibit different spectral properties. There are two species of acetic acid forming different complexes with solvent water molecules. The time constants are almost the same for CH3COOD and CD3COOD, suggesting that the vibrational energy deposited to the carbonyl group is first distributed among vibrational modes not related to the methyl group.
通过频率分辨红外泵浦-探测光谱研究了D2O中CH3COOD和CD3COOD的羰基CO伸缩振动模式的振动能量弛豫。振动激发引起的光谱变化包括两个动力学成分，CH3COOD的时间常数为450和980飞秒，CD3COOD的时间常数为390和930飞秒。这两个动力学成分表现出不同的光谱特性。有两种乙酸与溶剂水分子形成不同的络合物。CH3COOD和CD3COOD的时间常数几乎相同，这表明沉积到羰基的振动能量首先在与甲基无关的振动模式之间分布。
