Zuber Gérard, Wipf Peter, Beratan David N
Department of Chemistry, Duke University, Durham, North Carolina 27708, USA.
Chemphyschem. 2008 Feb 1;9(2):265-71. doi: 10.1002/cphc.200700660.
Rayleigh optical activity (RayOA) spectroscopy promises to provide an elegant and robust analytical method to probe molecular stereochemistry. A careful selection of RayOA variants such as right-angle depolarized ICP (incident circular polarization) or backscattering DCP(I) (in-phase dual circular polarization) allows analysis of the anisotropic component of the scattered light. In this study, we show that calculated anisotropic Rayleigh optical activity quantities provide key advantages over isotropic chiroptical quantities (such as optical rotation and RayOA variants dominated by isotropic invariants): 1) higher sensitivity for probing the chiroptical tensor G', 2) reduced dependence on small geometry changes, and 3) much less stringent computational demand for predicting an accurate sign than for optical rotation. Moreover, the stereochemical information provided by anisotropic RayOA and its invariants can be used to develop chirality descriptors because of the apparent correlation between structure/stereochemistry and the sign and magnitude of the anisotropic Rayleigh optical activity quantities.
瑞利光学活性（RayOA）光谱有望提供一种优雅且强大的分析方法来探测分子立体化学。仔细选择RayOA变体，如直角去偏振ICP（入射圆偏振）或背散射DCP(I)（同相双圆偏振），可以分析散射光的各向异性成分。在本研究中，我们表明，计算得到的各向异性瑞利光学活性量比各向同性手性光学量（如旋光性和由各向同性不变量主导的RayOA变体）具有关键优势：1）探测手性光学张量G'时具有更高的灵敏度，2）对小几何变化的依赖性降低，3）预测准确符号时的计算需求远不如旋光性严格。此外，由于结构/立体化学与各向异性瑞利光学活性量的符号和大小之间存在明显的相关性，各向异性RayOA及其不变量提供的立体化学信息可用于开发手性描述符。
