Panman Matthijs R, van Dijk Chris N, Meuzelaar Heleen, Woutersen S
Van 't Hoff Institute for Molecular Sciences, Universiteit van Amsterdam, Amsterdam, The Netherlands.
J Chem Phys. 2015 Jan 28;142(4):041103. doi: 10.1063/1.4906456.
We present a simple method to measure the dynamics of cross peaks in time-resolved two-dimensional vibrational spectroscopy. By combining suitably weighted dispersed pump-probe spectra, we eliminate the diagonal contribution to the 2D-IR response, so that the dispersed pump-probe signal contains the projection of only the cross peaks onto one of the axes of the 2D-IR spectrum. We apply the method to investigate the folding dynamics of an alpha-helical peptide in a temperature-jump experiment and find characteristic folding and unfolding time constants of 260 ± 30 and 580 ± 70 ns at 298 K.
我们提出了一种简单的方法来测量时间分辨二维振动光谱中交叉峰的动力学。通过组合适当加权的分散泵浦 - 探测光谱，我们消除了对二维红外响应的对角贡献，从而使分散泵浦 - 探测信号仅包含交叉峰在二维红外光谱轴之一上的投影。我们将该方法应用于温度跳跃实验中研究α - 螺旋肽的折叠动力学，发现在298 K时特征折叠和展开时间常数分别为260±30和580±70 ns。
