Mancinelli Michele, Franzini Roberta, Renzetti Andrea, Marotta Emanuela, Villani Claudio, Mazzanti Andrea
Department of Industrial Chemistry "Toso Montanari", University of Bologna Viale Risorgimento 4 40136-Bologna Italy
Dipartimento di Chimica e Tecnologie Del Farmaco, Sapienza Università di Roma P.le A. Moro 5 00185 Roma Italy
RSC Adv. 2019 Jun 10;9(32):18165-18175. doi: 10.1039/c9ra03526e.
The assignment of the absolute configuration (AC) of two conformational flexible organic molecules by means of TD-DFT simulation of the electronic circular dichroism (ECD) spectra is presented. The factors leading to a reliable assignment were evaluated in the various steps of the process. The effects of different functionals and basis sets in the geometry optimization step is very limited in terms of the resulting optimized geometries, whereas the inclusion of the solvent in the calculations has a much larger effect on the correct evaluation of the conformational ratio. B3LYP and M06-2x were found to be the most accurate functionals for geometry optimization. CAM-B3LYP and ωB97X-D provided the best results in the TD-DFT simulations.
本文介绍了通过电子圆二色光谱（ECD）的TD-DFT模拟来确定两个构象灵活的有机分子的绝对构型（AC）。在该过程的各个步骤中，对导致可靠构型确定的因素进行了评估。在几何优化步骤中，不同泛函和基组对最终优化几何结构的影响非常有限，而在计算中包含溶剂对构象比例的正确评估有更大影响。发现B3LYP和M06-2x是几何优化中最准确的泛函。CAM-B3LYP和ωB97X-D在TD-DFT模拟中提供了最佳结果。
