Naraharisetty Sri Ram G, Kasyanenko Valeriy M, Rubtsov Igor V
Department of Chemistry, Tulane University, New Orleans, LA 70118, USA.
J Chem Phys. 2008 Mar 14;128(10):104502. doi: 10.1063/1.2842071.
The relaxation-assisted two-dimensional infrared (RA 2DIR) method is a novel technique for probing structures of molecules, which relies on vibrational energy transport in molecules. In this article we demonstrate the ability of RA 2DIR to detect the bond connectivity patterns in molecules using two parameters, a characteristic intermode energy transport time (arrival time) and a cross-peak amplification coefficient. A correlation of the arrival time with the distance between the modes is demonstrated. An 18-fold amplification of the cross-peak amplitude for the modes separated by approximately 11 A is shown using RA 2DIR; larger cross-peak amplifications are expected for the modes separated by larger distances. The RA 2DIR method enhances the applicability of 2DIR spectroscopy by making practical the long-range measurements using a variety of structural reporters, including weak IR modes. The data presented demonstrate the analytical power of RA 2DIR which permits the speedy structural assessments of the bond connectivity patterns.
弛豫辅助二维红外（RA 2DIR）方法是一种探测分子结构的新技术，它依赖于分子中的振动能量传输。在本文中，我们展示了RA 2DIR利用两个参数检测分子中键连接模式的能力，这两个参数是特征模间能量传输时间（到达时间）和交叉峰放大系数。证明了到达时间与模式之间距离的相关性。使用RA 2DIR显示，对于相隔约11埃的模式，交叉峰幅度放大了18倍；对于相隔更远距离的模式，预计会有更大的交叉峰放大。RA 2DIR方法通过使用包括弱红外模式在内的各种结构报告基团进行远程测量，增强了二维红外光谱的适用性。所呈现的数据证明了RA 2DIR的分析能力，它能够快速对键连接模式进行结构评估。
