o(III)ED3A类及相关配体配合物CD谱反常邻位效应的理论解析
heoretical Analysis of the Unusual Vicinal Effects on Electronic Circular Dichroism Spectra of Cobalt(III) Complexes with ED3A-type and Related Ligands
本文利用量子化学密度泛函理论方法，在水溶液中用B3P86/6-311++G(2d,p)方法优化ED3A作为五齿配体的[Co(ED3A)NO2]-及其衍生物等5种手性配合物的基态构型，并用TDDFT方法计算它们的激发态性质，采用Gauss线性拟合的方法绘制园二色谱图。与实验谱相比，计算谱虽然有一定的蓝移或红移但是整体的带型和符号吻合较好。通过分析它们的邻位效应，发现在该类配合物中取代效应和结构弛豫效应符号相同，起拮抗作用。这使得使旋转强度减小，甚至使CD谱的符号发生改变。 然而在Co(III)EDDA-type配合物中却没有观察到这种现象。因此，在这类配合物中，除了螯合物的构型和环的构象外，邻位效应也是的主要手性来源之一。这些发现可以使我们更好地理解配合物的手性光学特征和立体化学结构之间的关系。
In the paper, the ground-state configurations of [Co(ED3A)NO2]-、[Co(ED3A)CN]-and derivatives have been performed at the DFT/B3P86/6-311++G(2d, p) level. And then Calculations of the excitation energies, oscillator and rotational strengths, and the CD spectra of the chelates of first 50 low-energy excited using the time-dependent density functional theory (TDDFT) method with the same functional and basis set considering solvent effect.The calculated circular dichroism (CD) curves are in excellent agreement with the observed ones except for some small red or blue shifts in peak wavelengths. Within the range of experimental wavelengths, the analysis of the vicinal effects shows that the signs of the substitutent effects and conformational relaxation effects being contrary. Even the contributions make the the sign of CD spectra changed. Thus, the vicinal effects also is a major source of optical activity. This findings make us better to understand the relationship between the optical activity and stereochemical structure.
王越奎、张春霞
化学物理学
ED3A类配合物邻位效应(含时)密度泛函理论方法圆二色谱
ED3A-type complexvicinal effectsDFT/TDDFTCD spectra
王越奎,张春霞.o(III)ED3A类及相关配体配合物CD谱反常邻位效应的理论解析[EB/OL].(2014-03-14)[2025-08-16].http://www.paper.edu.cn/releasepaper/content/201403-485.点此复制
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