2001 Fiscal Year Final Research Report Summary
超分子結晶中でのシッフ塩基類の異性化機構の解明と新規プロトン移動系の構築
| Project/Area Number |
11640538
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Organic chemistry
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
KAWATO Toshio Faculty of Sciences, Kyushu University Prof., 大学院・理学研究院, 教授 (40038477)
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| Co-Investigator(Kenkyū-buntansha) |
AMIMOTO Kiichi Res. Center for Higher Education, Res. Ass., 大学教育研究センター, 助手 (60294873)
KOYAMA Hiroyuki Faculty of Sciences, Kyushu University Prof., 大学院・理学研究院, 教授 (10038490)
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| Project Period (FY) |
1999 – 2001
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| Keywords | photochromism / photoisomerization / solid-state reaction / inclusion crystals / supramolecula chemistry / N-salicylideneamline / Schiff base / deoxycholic acid |
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| Research Abstract |
N-{3,5-bis(1-methyl-1-phenylethyl)salicylidene}-4-trityl-aniline and its clathrate crystals with methanol and acetone were prepared. The yielded crystals were photochromic; each photo-colored species was obtained by irradiating crystalline powder with 365 nm light. The large substituents on both aromatic rings were found not to disturb the occurrence of photochromism of salicylideneaniline. The degrees of the spectral changes after UV irradiation for the solvent clathrate compounds were much smaller than that of pure host Schiff base crystals. The maximum changes in optical density were observed at 481 nm for the parent Schiff base and 499 nm for both solvent adducts. Thermal stability of the photochrome depended on the solvent included. Thus, solvent effects were observed on the solid-phase photoisomerization of the Schiff base. Definite clathrate crystals of deoxycholic acid and its amide and alcohol derivatives as host molecules with N-salicylideneaniline as a guest molecule were pr
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epared to investigate their photochromic properties. All these clathrate crystals exhibited photochromism by irradiating the crystal powder with 365 nm light. Rate constants of the thermal fading of the photochromes were measured to be distinct in the different clathrate environments. From the sharp difference in the first-order rate constants of the thermal bleaching of the photochromes, it was found that the thermal unimolecular motion of photo-colored species was strongly influenced by the neighboring environments in the crystal state. These results demonstrate that the photochromic process of Schiff bases is delicate and a small change of supramolecular environment influences strongly the photochromic properties in the crystal state.
In order to develop a new series of supramolecular systems, we prepared a series of 2,6-bis(2,2'-dicarbalkoxyethyl)pyridine ligands and their Pd(ll)-complexes. A couple of the ligands linked by a trans-PdCl2 unit were found toextract alkali metal ions from an aqueous media into a chloroform media, while a single pyridine ligand did not work as an extractive reagent. In general, acyclic host molecules have the advantage of easy synthesis and high versatility of the structure. Thus, 2,6-difunctionalized pyridines and related derivatives are expected to develop into a new type of supramolecular systems to pick up selected chemical species by the aid of trans-metal complexation which grips the coupled host molecules in the right way. Of the potential variations on our general strategy, a study on the inclusion of a neutral molecule into such a Pd(ll) complex with condensed-ring subunits is now under investigation. Less
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Research Products
(6 results)
