Direct Observation of the Coherent Nuclear Response after the Absorption of a Photon
Direct Observation of the Coherent Nuclear Response after the Absorption of a Photon
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DOI：
10.1103/physrevlett.112.238301
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发表时间：
2014-06-09
影响因子：
8.6
通讯作者：
Kukura, P.
中科院分区：
文献类型：
--
作者：
Liebel, M.;Schnedermann, C.;Kukura, P.
分子如何转换光能来执行特定的转换是光物理学中的一个基本问题。超快光谱学揭示了与电子能量流有关的动力学，但对吸收的光子能量如何驱动核运动知之甚少。在这里，我们使用超宽带瞬时吸收光谱来监测光激发视网膜生色团后的相干振动能流。在质子泵细菌视紫红质中，我们观察到氢平面外摆动和主干扭转模式的相干激活，这些模式在溶液环境中被非反应坐标取代，伴随着反应弛豫途径的失活。
How molecules convert light energy to perform a specific transformation is a fundamental question in photophysics. Ultrafast spectroscopy reveals the kinetics associated with electronic energy flow, but little is known about how absorbed photon energy drives nuclear motion. Here we used ultrabroadband transient absorption spectroscopy to monitor coherent vibrational energy flow after photoexcitation of the retinal chromophore. In the proton pump bacteriorhodopsin, we observed coherent activation of hydrogen-out-of-plane wagging and backbone torsional modes that were replaced by unreactive coordinates in the solution environment, concomitant with a deactivation of the reactive relaxation pathway.