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PERSUIT OF CHEMISTRY TO VISUALIZE VAN DER WAALS FORCE

利用化学来可视化范德瓦尔斯力

基本信息

批准号：
09640660
负责人：
OHTA Kazuchika
金额：
$ 2.18万
依托单位：
Shinshu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 2000
项目状态：
已结题

项目摘要

Columnar liquid crystalline bis[1,2-big(3,4-di-n-alkoxyphenyl)ethanedione dioximato]d^8 metal(II)complexes were successfully synthesized. Thermochromism of these liquid crystals is caused by fastening of the central metals by the surrounding long chains. We found that van der Waals force of the long chains can be visualized. "Apparent pressure" of the long chains for these(C_nO)_<8->M complexes could be estimated by using shift coefficients of the d-p band for the non-substituted core complex. Nevertheless, it was still ambiguous whether the metal-metal distance is elongated or the one-dimensionally stacked metals become to slip with heating, to cause the mesomorphic thermocromism. Hence, XANES spectra of the nickel complex were recorded and analyzed by using DV-Xα method. It was established for the first time that the one-dimensionally stacked metals slip with heating.Then, the critical molecular structure change from columnar to lamellar mesophases in this system was investigated. When the number of the long chains surrounding the core complex part was reduced from eight to four, the mesophase changes its structure from columnar Col_<hd> to novel discotic lamellar D_<L.rec>(P2_12_1).Interestingly, these present metal complexes form gels in an over-concentrated nhexane solution. In order to determine the structure of the gel by X-ray diffraction technique, a specific cell was developed. The gel has a two-dimensional hexagonal structure which is similar to the inverted hexagonal phase of lyotropic liquid crystals.Polymerization of these present disk-like big(glyoximato)d^8 metal(II)complexes enables us to develop a novel functional material changing the color with pressure and/or temperature. Hence, the various synthetic routes were investigated and then a nickel complex having polymerizable groups has been successfully synthesized. We plan to synthesize a large amount of the complex in the next stage.

成功地合成了柱状液晶双[1，2-大(3，4-二正烷氧基苯基)乙二酮]d^8金属(II)配合物。这些液晶的热致变色是由于中心金属被周围的长链固定而引起的。我们发现长链的范德华力是可视的。利用未取代核络合物d-p带的位移系数，可以估算出这些(C_NO)_8-Gt；M络合物的长链“表观压力”。然而，金属-金属之间的距离是否被拉长，或者一维堆积的金属随着加热而滑移，从而导致介晶性热色变，仍然是一个未知数。因此，用DV-Xα方法记录和分析了镍配合物的XANES光谱。首次证实了一维堆积金属在加热过程中的滑移现象，并研究了该体系中从柱状到片状中间相的临界分子结构变化。当围绕核心络合物部分的长链从8个减少到4个时，中间相的结构从柱状的Col_&lt；HD&gt；转变为新的盘状片状D_&lt；L.rec&gt；(P2_12_1)。有趣的是，这些金属络合物在过浓的正己烷溶液中形成凝胶。为了用X射线衍射法确定凝胶的结构，研制了一种特异池。这种凝胶具有类似于溶致液晶的倒六方相的二维六方结构，这些目前存在的盘状大(乙二酮亚胺)d^8金属(II)配合物的聚合使我们能够开发出一种新型的功能材料，其颜色随着压力和/或温度的变化而变化。因此，研究了不同的合成路线，并成功地合成了一种具有可聚合基团的镍配合物。我们计划在下一阶段合成大量的络合物。