Department of Chemistry, University of Central Florida, P.O. Box 162366, Orlando, Florida 32816-2366, USA.
J Phys Chem A. 2013 Sep 5;117(35):8416-26. doi: 10.1021/jp4065714. Epub 2013 Aug 23.
Herein we report on the conformational study of a chiral Salen ligand, AFX-155, in THF solution using two-photon absorption (TPA) and, even more importantly, two-photon circular dichroism (TPCD). The fragment-recombination approach (FRA), employed to perform computations on half-AXF-155 (AXF-169') and the center (C-AXF-155), allowed us to overcome the current computational limitations found in calculations of the TPCD spectra of large molecules. The comparative experimental-theoretical analysis of AXF-155 showed that its TPA is mainly determined by AXF-169' and validated, through TPCD, the presence of the two dominant Trans_R-Intra(NHB)//Trans_R-Extra(HB) and Trans_R-Intra(NHB)//Trans_R-Extra(NHB) structure in THF with a ΔΔ propeller chirality on the diphenylamine moieties at the end of each AXF-169'. The application of FRA for the analysis of the TPCD spectra of large chiral molecules has been proven to be effective.
在这里，我们报告了手性 Salen 配体 AFX-155 在 THF 溶液中的构象研究，使用了双光子吸收（TPA），更重要的是，双光子圆二色性（TPCD）。碎片-重组方法（FRA）用于对半 AFX-155（AXF-169'）和中心（C-AFX-155）进行计算，克服了当前计算大分子 TPCD 光谱时发现的计算限制。对 AXF-155 的实验-理论比较分析表明，其 TPA 主要由 AXF-169'决定，并通过 TPCD 验证了在 THF 中存在两种主要的 Trans_R-Intra(NHB)//Trans_R-Extra(HB)和 Trans_R-Intra(NHB)//Trans_R-Extra(NHB)结构，每个 AXF-169'末端的二苯胺部分具有 ΔΔ 桨型手性。FRA 用于分析大的手性分子的 TPCD 光谱已被证明是有效的。
