Circular Dichroism of Crystals

晶体的圆二色性

• 批准号: 14340220
• 负责人: KOSHIMA Hideko
• 金额: $ 9.6万
• 依托单位: Ehime University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14340220/
• 关键词: Crystal Optical Activity; Circular Dichroism Spectra; Optical Rotatory Power; Chiral Crystals; Organic Crystals; Birefringence; Chirality; Helical Structure; 光学活性特性

Every chiral organic crystal has inherent optical activity. The sign and the magnitude of the optical activity of an organic crystal should reflect the molecular structure as well as the packing arrangement because the freedom of molecules is severely restricted in the crystal lattice, which is very different from the high mobility of molecules in solution. However, the optical activity of organic crystals has been scarcely measured and therefore never correlated with the crystal structure until the present time. The reason for this is that the measurement of optical activity of a crystal is accompanied with much difficulty due to birefringence being 10^3 times larger birefringence than the gyration tensor, so in this case the latter effect is masked. A few years ago, we first introduced a high accuracy universal polarimeter (HAUP) in chemistry. Recently, we prepared a new version of HAUP in order to measure circular dichroism spectra of crystals. Now the check of performance is in progress.Herein the rotatory powers of helical-type cocrystal formed between tryptamine and 4-chlorobenzoic acid were determined by the HAUP method. After much trial and error, we could overcome the sample polish problem by using soft Fe_2O_3 polish agent and obtain satisfactorily the rotatory powers of the cocrystal from tryptamine and 4-chlorobenzoic acid. The results revealed that the helically arranged aromatic π electrons as well as the helical ionic and hydrogen bond networks in the crystal contributed to the enhancement of the magnitude of these rotations. This is the the first measurement of the optical activity of organic-organic cocrystal formed from two different achiral molecules.

每个手性有机晶体都具有固有的光学活性。有机晶体旋光性的符号和大小应反映分子结构以及堆积排列，因为分子的自由度在晶格中受到严格限制，这与溶液中分子的高迁移率有很大不同。然而，有机晶体的光学活性几乎没有被测量过，因此直到现在才与晶体结构相关。其原因是，由于双折射比回转张量大10^3倍，因此晶体旋光性的测量伴随着很大的困难，因此在这种情况下，后者的影响被掩盖了。几年前，我们首次在化学领域推出高精度通用旋光仪（HAUP）。最近，我们准备了新版本的HAUP来测量晶体的圆二色光谱。目前性能检验正在进行中。本文采用HAUP法测定了色胺与4-氯苯甲酸形成的螺旋型共晶的旋光度。经过反复试验，采用软Fe_2O_3抛光剂克服了样品抛光问题，并获得了满意的色胺和4-氯苯甲酸共晶的旋转能力。结果表明，晶体中螺旋排列的芳香π电子以及螺旋离子和氢键网络有助于增强这些旋转的幅度。这是首次测量由两种不同非手性分子形成的有机-有机共晶体的光学活性。

项目成果

H.Koshima, M.Hamada, M.Tani, S.Iwasaki, F.Sato: "High-throughput Synthesis of Symmetrically 3,5-Disubstituted 4-Amino-1,2,4-tnazoles from Aldehydes Using Microwave"Heterocycles. 57. 2145-2148 (2002)

H.Koshima、M.Hamada、M.Tani、S.Iwasaki、F.Sato：“使用微波从醛中高通量合成对称 3,5-二取代的 4-氨基-1,2,4-三唑”杂环。

H.Koshima: "Organic Solid State Reactions"Kluwer Academic Publishers. 275 (2002)

H.Koshima：《有机固态反应》Kluwer 学术出版社。

H.Koshima: "Chiral Photochemistry"Marcel Dekker, Inc.(In press).

H.Koshima：“手性光化学”Marcel Dekker, Inc.（正在出版）。

H.Koshima, M.Hamada: "Solvent-free Condensation of Aromatic Aldehydes and 2,3-Dimethyl-1-phenyl-3-pyrazolin-5-one Catalyzed by p-Toluenesulfonic Acid"Journal of Heterocyclic Chemistry. 39. 1087-1088 (2002)

H.Koshima，M.Hamada：“对甲苯磺酸催化的芳香醛与 2,3-二甲基-1-苯基-3-吡唑啉-5-酮的无溶剂缩合”杂环化学杂志。

H.Koshima, A.Nakata, M.Nagano, H.Yu: "Photoreaction of 9-Methylbenz[c]acridine with Diphenylacetic Acid in the Chiral Cocrystal"Heterocycles. 60. 2251-2258 (2003)

H.Koshima、A.Nakata、M.Nagano、H.Yu：“手性共晶中 9-甲基苯并[c]吖啶与二苯乙酸的光反应”杂环。