This work demonstrates resonance Raman optical activity (RROA) spectra of three truncated vitamin B12 derivatives modified within the nucleotide loop. Since truncated cobalamins possess sufficiently high rotational strength in the range of ROA excitation (532 nm), it was possible to record their spectra in the resonance condition. They showed several distinct spectral features allowing for the distinguishing of studied compounds, in contrast to other methods, i.e., UV-Vis absorption, electronic circular dichroism, and resonance Raman spectroscopy. The improved capacity of the RROA method is based here on the excitation of molecules via more than two electronic states, giving rise to the bisignate RROA spectrum, significantly distinct from a parent Raman spectrum. This observation is an important step in the dissemination of using RROA spectroscopy in studying the complex structure of corrinoids which may prove crucial for a better understanding of their biological role.

中文翻译：

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共振拉曼光学活动光谱探测圆二色光谱不可见的结构变化：截短维生素 B12 衍生物的研究

这项工作展示了在核苷酸环内修饰的三种截短的维生素 B12 衍生物的共振拉曼光学活性 (RROA) 光谱。由于截断的钴胺素在 ROA 激发范围内 (532 nm) 具有足够高的旋转强度，因此可以在共振条件下记录它们的光谱。与其他方法（即 UV-Vis 吸收、电子圆二色性和共振拉曼光谱）相比，它们显示了几种不同的光谱特征，可以区分所研究的化合物。RROA 方法的改进能力在这里基于通过两个以上电子态激发分子，产生双信号 RROA 光谱，与母拉曼光谱显着不同。