Following photoinduced dynamics in bacteriorhodopsin with 7-fs impulsive vibrational spectroscopy

被引：0

作者：

Kahan, Anat ^{[1
]}

Nahmias, Omer ^{[1
]}

Friedman, Noga ^{[2
]}

Sheves, Mordechai ^{[2
]}

Ruhman, Sanford ^{[1
]}

机构：

[1] Department of Physical Chemistry, Farkas Center for Light Induced Processes, Hebrew University, Jerusalem 91904, Israel

[2] Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel

来源：

Journal of the American Chemical Society | 2007年 / 129卷 / 03期

关键词：

Sub-10-fs laser pulses are used to impulsively photoexcite bacteriorhodopsin (BR) suspensions and probe the evolution of the resulting vibrational wave packets. Fourier analysis of the spectral modulations induced by transform-limited as well as linearly chirped excitation pulses allows the delineation of excited- and ground-state contributions to the data. On the basis of amplitude and phase variations of the modulations as a function of the dispersed probe wavelength; periodic modulations in absorption above 540 nm are assigned to ground-state vibrational coherences induced by resonance impulsive Raman spectral activity (RISRS). Probing at wavelengths below 540 nm-the red edge of the intense excited-state absorption band-uncovers new vibrational features which are accordingly assigned to wave packet motions along bound coordinates on the short-lived reactive electronic surface. They consist of high- and low-frequency shoulders adjacent to the strong C=C stretching and methyl rock modes; respectively; which have ground-state frequencies of 1008 and 1530 cm-1. Brief activity centered at ∼900 cm-1; which is characteristic of ground-state HOOP modes; and strong modulations in the torsional frequency range appear as well. Possible assignments of the bands and their implication to photoinduced reaction dynamics in BR are discussed. Reasons for the absence of similar signatures in the pump-probe spectral modulations at longer probing wavelengths are considered as well. © 2007 American Chemical Society;

D O I：

暂无

中图分类号：

学科分类号：

摘要：

Journal article (JA)

引用

页码：537 / 546