VIBRATIONALLY COHERENT PHOTOCHEMISTRY IN THE FEMTOSECOND PRIMARY EVENT OF VISION
VIBRATIONALLY COHERENT PHOTOCHEMISTRY IN THE FEMTOSECOND PRIMARY EVENT OF VISION
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DOI：
10.1126/science.7939680
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发表时间：
1994-10-21
期刊：
影响因子：
56.9
通讯作者：
SHANK, CV
中科院分区：
文献类型：
--
作者：
WANG, Q;SCHOENLEIN, RW;SHANK, CV
飞秒泵浦-探测实验揭示了视觉初级事件中光产物的脉冲产生。在500纳米处用35飞秒脉冲激发视紫红质的视网膜发色团，并用10飞秒探测脉冲测量吸收的瞬态变化。在探测波长内的photoproduct吸收带，周期为550飞秒（60波数）的振荡功能进行了观察，其相位和振幅表明，它们是在基态的photoproduct的非稳态振动运动的结果。光产物的相干振动运动的观察支持了这样的想法，即视觉的主要步骤是振动相干过程，并且视紫红质中顺式->反式异构化的高量子产率是激发态扭转运动的极端速度的结果。
Femtosecond pump-probe experiments reveal the impulsive production of photoproduct in the primary event in vision. The retinal chromophore of rhodopsin was excited with a 35-femtosecond pulse at 500 nanometers, and transient changes in absorption were measured with 10-femtosecond probe pulses. At probe wavelengths within the photoproduct absorption band, oscillatory features with a period of 550 femtoseconds (60 wavenumbers) were observed whose phase and amplitude demonstrate that they are the result of nonstationary vibrational motion in the ground state of the photoproduct. The observation of coherent vibrational motion of the photoproduct supports the idea that the primary step in vision is a vibrationally coherent process and that the high quantum yield of the cis-->trans isomerization in rhodopsin is a consequence of the extreme speed of the excited-state torsional motion.