Department of Chemistry, School of Science, Tokyo Institute of Technology.
Proc Jpn Acad Ser B Phys Biol Sci. 2024;100(2):101-113. doi: 10.2183/pjab.100.003.
In 1932, Mizushima and Higasi reported the dependence of the dipole moments of 1,2-dichloroethane on both temperature and solvent in the Proceedings of the Imperial Academy, Japan. This report was followed by their first proposal of the existence of conformers that exchanged by internal rotation about a C-C single bond based on experimental data. Their monumental work marked the beginning of the essential concept of conformation in modern stereochemistry. Their proposal was later confirmed by the direct observation of the anti and gauche conformers of 1,2-dichloroethane by Raman spectroscopy, and further supported by other experimental and theoretical methods. The relative stabilities of the anti and gauche conformers of 1,2-dichloroethane and other 1,2-disubstituted ethanes were discussed in terms of steric, electrostatic, and stereoelectronic effects based on analysis of calculated data. Those studies influenced the development of subsequent research in organic chemistry, such as the conformational analysis of cyclohexane derivatives and the isolation of chiral gauche conformers.
1932 年，水岛三和东井在日本帝国科学院会议录上报道了 1,2-二氯乙烷的偶极矩随温度和溶剂变化的依赖性。这一报告之后，他们基于实验数据首次提出了存在通过 C-C 单键内旋转交换的构象体的观点。他们的这项重要工作标志着现代立体化学中构象基本概念的开始。他们的观点后来通过拉曼光谱直接观察到 1,2-二氯乙烷的反式和重叠构象得到了证实，并通过其他实验和理论方法得到了进一步支持。根据计算数据的分析，从空间位阻、静电和立体电子效应的角度讨论了 1,2-二氯乙烷和其他 1,2-二取代乙烷的反式和重叠构象的相对稳定性。这些研究影响了有机化学后续研究的发展，例如环己烷衍生物的构象分析和手性重叠构象的分离。
