Thiourea and isothiocyanate – two useful chromophores for stereochemical studies. A comparison of experiment and computation
摘要:
硫脲和异硫氰酸盐是有机合成中非常重要的化合物,但迄今为止还没有人认为它们是可以通过分析圆二色光谱提供结构信息的光电探针。我们获得了一组含有硫脲、异硫氰酸盐和邻苯二甲酰亚胺发色团的分子的 CD 光谱,并根据计算得出的构象群及其对 CD 光谱的单独贡献进行了分析。研究表明,硫脲和异硫氰酸盐发色团可以通过分析其激子耦合 CD 光谱提供有用的结构信息。研究发现,硫脲的激子耦合 CD 光谱对发色团的 Z/E 构象很敏感。与传统使用的 B3LYP 函数相比,基于 B2LYP 函数的 DFT 计算能更好地匹配短波长区域的实验光谱。
Thiourea and isothiocyanate – two useful chromophores for stereochemical studies. A comparison of experiment and computation
作者:Jacek Gawronski、Marcin Kwit、Pawel Skowronek
DOI:10.1039/b821335f
日期:——
Thioureas and isothiocyanates, compounds of high importance in organic synthesis, have not been considered so far as chiroptical probes that can provide structural information from the analysis of circular dichroism spectra. CD spectra of a set of molecules containing the thiourea, isothiocyanate and phthalimide chromophores were obtained and analyzed on the grounds of the calculated populations of conformers and their individual contributions to the CD spectra. It is shown that the thiourea and isothiocyanate chromophores can provide useful structural information from the analysis of their exciton-coupled CD spectra. Exciton-coupled CD spectra of thioureas were found to be sensitive to the Z/E conformation of the chromophore. DFT calculations based on the B2LYP functional were shown to provide a better match with the experimental spectra collected in the short wavelength region, compared to the traditionally used B3LYP functional.
硫脲和异硫氰酸盐是有机合成中非常重要的化合物,但迄今为止还没有人认为它们是可以通过分析圆二色光谱提供结构信息的光电探针。我们获得了一组含有硫脲、异硫氰酸盐和邻苯二甲酰亚胺发色团的分子的 CD 光谱,并根据计算得出的构象群及其对 CD 光谱的单独贡献进行了分析。研究表明,硫脲和异硫氰酸盐发色团可以通过分析其激子耦合 CD 光谱提供有用的结构信息。研究发现,硫脲的激子耦合 CD 光谱对发色团的 Z/E 构象很敏感。与传统使用的 B3LYP 函数相比,基于 B2LYP 函数的 DFT 计算能更好地匹配短波长区域的实验光谱。