Probe-Wavelength Dependence of Picosecond Time-Resolved Anti-Stokes Raman Spectrum of Canthaxanthin: Determination of Energy States of Vibrationally Excited Molecules Generated via Internal Conversion from the Lowest Excited Singlet State
Probe-Wavelength Dependence of Picosecond Time-Resolved Anti-Stokes Raman Spectrum of Canthaxanthin: Determination of Energy States of Vibrationally Excited Molecules Generated via Internal Conversion from the Lowest Excited Singlet State
复制标题
角黄素皮秒时间分辨反斯托克斯拉曼光谱的探针波长依赖性：通过从最低激发单线态进行内部转换生成振动激发分子的能量状态的测定
DOI：
--
复制
发表时间：
1997
期刊：
影响因子：
--
通讯作者：
M. Tasumi
中科院分区：
文献类型：
--
作者：
T. Nakabayashi;H. Okamoto;M. Tasumi
利用皮秒时间分辨反斯托克斯拉曼光谱研究了角黄素从最低激发电子态（S1）内部转换到S 0态后，基态电子态（S 0）的振动弛豫过程。两个强反斯托克斯拉曼带的泵浦诱导强度在泵浦脉冲的延迟时间为12 ps时达到最大值，并以15 - 20 ps的时间常数衰减。瞬态“同相”CC拉伸反斯托克斯拉曼带的峰位置显示出从在稳态（cw）光谱中观察到的向较低频率的小位移。为了确定所观察到的振动激发的分子被填充的能级，泵浦诱导的反斯托克斯拉曼强度的探针波长依赖性进行了分析。大多数的振动激发瞬态引起的瞬态1520 cm-1带在延迟时间12 ps的CC伸缩模式在S 0状态的第一激发振动水平。这一结果表明...
The vibrational relaxation process in the ground electronic state (S0) of canthaxanthin after internal conversion from the lowest excited electronic state (S1) to the S0 state is studied by picosecond time-resolved anti-Stokes Raman spectroscopy. The pump-induced intensities of two strong anti-Stokes Raman bands reach their maxima at delay time ∼12 ps from the pump pulse, and decay with a time constant of 15−20 ps. The peak position of the transient “in-phase” CC stretching anti-Stokes Raman band shows a small shift to a lower frequency from that observed in the stationary (cw) spectrum. In order to determine the energy levels on which the observed vibrationally excited molecules are populated, the probe-wavelength dependence of the pump-induced anti-Stokes Raman intensities are analyzed. Most of the vibrationally excited transients giving rise to the transient 1520 cm-1 band at delay time 12 ps are on the first excited vibrational level of the CC stretching mode in the S0 state. This result suggests that...