光学纯隐色体-A的振动圆二色性研究。

Vibrational circular dichroism study of optically pure cryptophane-A.

作者信息

Brotin Thierry, Cavagnat Dominique, Dutasta Jean-Pierre, Buffeteau Thierry

机构信息

Laboratoire de Chimie de l'ENS-LYON (UMR 5182-CNRS), Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, 69364 Lyon 07, France.

出版信息

J Am Chem Soc. 2006 Apr 26;128(16):5533-40. doi: 10.1021/ja0603148.

DOI:10.1021/ja0603148

PMID:16620127

Abstract

Vibrational circular dichroism (VCD) measurements and density functional theory (DFT) calculations were used to obtain the absolute configuration of optically pure cryptophane-A molecule. This large molecule (120 atoms) that possess a globular shape, but no chiral centers, exceeds the molecular size of published structures for which VCD has been used to determine the absolute configuration. VCD spectra recorded in CDCl(3) solution for the two resolved enantiomers are near mirror images, and very good agreement between the observed IR and VCD spectra and intensity calculations performed at the DFT (B3PW91/6-31G) level establish, besides the absolute configuration, the preferential anti conformation of the aliphatic linkers of the chloroform-cryptophane-A complex. Experiments performed in CD(2)Cl(2) and C(2)D(2)Cl(4) solutions show no significant modifications in the IR and VCD spectra, indicating that the conformation of the aliphatic linkers is similar for empty (C(2)D(2)Cl(4) solution) and encaged (CDCl(3) and CD(2)Cl(2) solutions) cryptophane-A molecules.

摘要

振动圆二色性（VCD）测量和密度泛函理论（DFT）计算被用于确定光学纯的隐色烟碱-A分子的绝对构型。这种具有球状形状但没有手性中心的大分子（120个原子），其分子尺寸超过了已发表的使用VCD确定绝对构型的结构的分子尺寸。在CDCl₃溶液中记录的两种拆分对映体的VCD光谱近乎镜像，并且在DFT（B3PW91/6-31G）水平上进行的观察到的红外光谱和VCD光谱与强度计算之间的非常好的一致性，除了确定绝对构型之外，还确定了氯仿-隐色烟碱-A配合物脂肪族连接基的优先反式构象。在CD₂Cl₂和C₂D₂Cl₄溶液中进行的实验表明，红外光谱和VCD光谱没有明显变化，这表明对于空的（C₂D₂Cl₄溶液）和包封的（CDCl₃和CD₂Cl₂溶液）隐色烟碱-A分子，脂肪族连接基的构象相似。