Development of a new method for choromatographic resolution by use of a clay

在本项目中，我们试图开发一种使用粘土-螯合物作为填充材料来定量分离光学异构体的新的色谱方法。首先，Yamagishi和Matsushita试图扩大改进的粘土色谱柱在光学拆分中的适用范围。为此，几种光学活性金属络合物被用作粘土改性剂，如[Ru(Bpy)3]2+(bpy=2，2‘-联吡啶)和[Co(Phen)3]2+(pahen=1，10-邻菲咯啉)。结果表明，用光学活性的[Ru(Bpy)3]2+修饰的粘土可以拆分多种有机化合物。有趣的是，该柱与用Ru(Phen)32+修饰的柱具有不同的选择性。Co(Phen)32+修饰的色谱柱对光学活性有机化合物没有表现出明显的分离能力。这可能是因为络合物具有三个负电荷(+3e)，因此被吸附的络合物的表面密度太低…更重要的是要认识到正在接近的分子的柔韧性。换句话说，结果表明，拆分是在两个以上被吸附的螯合物之间的协同作用下实现的。其次，Ohtsu致力于将拆分物质的量从定性增加到定量。他开发了一种尺寸为60毫米的柱子(I.D.)×250 mm，并通过一次分离程序成功地拆分了1-2g的化合物，如Ru(Acac)3。[Ru(Acac)3]作为一种非线性光学材料最近引起了人们的关注。山下和松下拆分了氨基酸和二肽。结果表明，用光学活性[Ru(Phen)3]2+修饰的粘土(合成氢托石)柱可以拆分多种2，5-二硝基苯甲酰基修饰的氨基酸酯。此外，该色谱柱对相同基团修饰的丙氨酸丙二醇酯具有较高的拆分效率。利用核磁共振波谱对其在乙腈中的拆分机理进行了研究。最后，山西利用蒙特卡罗模拟方法对粘土对金属络合物的吸附进行了理论研究。结果表明，粘土的硅酸盐片层在用光学活性金属络合物修饰粘土的手性识别中起着主导作用。较少

In the present project, we have attempted to develop a new chromatographic method for the quantitative separation of an optical isomer using a clay-chelate adduct as a packing material.Firstly Yamagishi and Matsushita tried to widen the scope of applicability of a modified clay column for optical resolution. For that purpose, several kinds of optically active metal complexes were applied as a clay modifier such as [Ru(bpy)3]2+ (bpy = 2,2'-bipyridyl) and [Co(phen)3]2+ (pahen = 1,10-phenanthroline). As a result, a clay modified with optically active [Ru(bpy)3]2+ proved to resolve a number of organic compounds. Interestingly enough, the column exhibited different selectivity from the column modified with Ru(phen)3 2+. The column modified with Co(phen)3 2+ did not show any significant separation capability towardsan optically active organic compounds. This may be probably because the chelate posseses three negative charges (+3e) so that the surface density of the adsorbed chelate is too lo … More w to recognize the chility of an approaching molecule. In other words, the results suggest that the resolution is achieved under the cooperative interactions among more than two adsorbed chelates.Secondly Ohtsu has atempted to increase the amount of resolved material from the qualitative scale to the quantitative on. He developed a colum with a size of 60mm(i.d.) x 250 mm and succeeded in resolving 1 - 2 g of a compound such as Ru(acac)3 by one separation procedure. [Ru(acac)3] has been attracting a recent attention as a material for non-linear optics.Thirdly Yamagishi and Matsusita resolved amino acids and dipeptide. As a result, the column packed with a clay (synthetic hectorite) modified with optically active [Ru(phen)3]2+ has proved to resolve many kinds of amino acid esters modified with the 2,5-dinitrobenzoyl group. Moreover the column exhibited high resolution efficiency towards alanyl ala-nine ester modified with the same group. The resolution mechanisms were studied with NMR spectroscopy in acetonitrile.Lastly Yamagishi has performed the theoretical investigations on the adsorption of a metal complex by a clay by use of Monte Carlo simulation. As a result, it has been revealed that the silicate sheet of a clay has a dominant role in establishing the chirality recognition by a clay modified with an optically active metal complex. Less