pressure dependence of the conformational transition of linear chain compounds

直链化合物构象转变的压力依赖性

• 批准号: 10640492
• 负责人: FUKUHARA Koichi
• 金额: $ 2.05万
• 依托单位: Hiroshima University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10640492/
• 关键词: high pressure infrared spectroscopy; block oligomers; conformational transition

The oxyethylene chain usually takes a helical conformation in the solid state. On the other hand, a planar zigzag modification of the oxyethylene block is found in a series of alkyl-oxyethylene block oligomers (CィイD2nィエD2EィイD2mィエD2, CィイD2nィエD2EィイD2mィエD2CィイD2nィエD2) in the solid state. The planar zigzag structure of the oxyethylene block is stabilized by cohesive force of the crystal lattice of the planar zigzag alkyl block(s). Since external pressure influences the molecular conformation as a similar manner of the intermolecular cohesive force, we have tried to observe a pressure-induced crystallization and conformational transition of diblock oligdmers CィイD210ィエD2EィイD2mィエD2 by using high pressure.Pressure induced crystallization and conformation transition were studied by infrared spectroscopy equipped with a high-pressure diamond anvil cell. Calcium fluoride was selected as a pressure-transmitting medium. Ruby fluorescence was used to calibrate the in-situ pressure.The following results were obtained in this study :1. The molecular conformation of the CィイD210ィエD2EィイD2mィエD2 compounds depends on the block length. While the oxyethylene block assumes the planar zigzag conformation for m = 1-4, the oxyethylene block assumes the helical conformation for m = 7 and 8.2. In case of m = 5 and 6, the conformation of the oxyethylene block depends on the rate of compression.The planar zigzag conformation was obtained by a rate more than ca. 0.5 GPa/sec. On the other hand, the helical conformation was obtained by a rate less than 1 GPa/min. or by annealing the solid.3. Pressure-induced amorphization was observed for the solid of CィイD210ィエD2EィイD2mィエD2 having the helical oxyethylene block.

氧乙烯链在固体状态下通常呈螺旋形。另一方面，在固体状态下，在一系列烷基氧乙烯嵌段低聚物（C γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ）中发现了氧乙烯嵌段的平面之字形修饰。氧乙烯块的平面之字形结构是由平面之字形烷基块的晶格内聚力稳定的。由于外部压力对分子构象的影响与分子间内聚力的影响类似，我们试图用高压观察压力诱导的二嵌段低聚物C γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ的结晶和构象转变。利用红外光谱技术研究了高压金刚石顶砧细胞的压力诱导结晶和构象转变。选择氟化钙作为传压介质。采用红宝石荧光法标定原位压力。本研究的主要结果如下：1。C γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ。当m = 1-4时，氧乙烯块呈平面之字形构象，而当m = 7和8.2时，氧乙烯块呈螺旋状构象。在m = 5和6的情况下，氧乙烯块的构象取决于压缩速率。以大于0.5 GPa/s的速率得到平面之字形构象。另一方面，螺旋构象的形成速率小于1 GPa/min。或者把固体退火。结果表明，具有螺旋型氧乙烯嵌段的C‑‑D210‑‑D2E‑‑D2m‑‑D2固体存在压力诱导非晶化现象。

项目成果

福原 幸一: "Block crystallization effect on the conformation of triblock olifomers α-n-alkyl-ω-n-alkoxyoligo(oxyethylene)s in the solid state"Journal of Molecular Structure. 523(1-3). 269-280 (2000)

Koichi Fukuhara：“嵌段结晶对固态三嵌段低聚体 α-n-烷基-ω-n-烷氧基低聚（氧乙烯）的影响”《分子结构杂志》523(1-3) (2000)。 ）

Koichi Fukuhara, Kenji Hashiwata, Kaori Takayama, Hiroatsu Matsuura: "Block crystallization effect on the conformation of triblock oligomers α-n-alkyl-ω-n-alkoxyoligo(oxyethylene)s in the solid state"Journal of Molecular Structure. 523(1-3). 269-280 (2000

Koichi Fukuhara、Kenji Hashiwata、Kaori Takayama、Hiroatsu Matsuura：“块结晶对固态三嵌段低聚物 α-n-烷基-ω-n-烷氧基寡聚（氧乙烯）的构象的影响”《分子结构杂志》523（1）。 ）-3）。269-280（2000）。

福原 幸一: "Block crystallization effect on the conformation of triblock oligomers α-n-alhyl -ω-n-alkoxvoligo(oxvethlene)s in the solid state"Journal of Molecular Structure. 523(1-3). 269-280 (2000)

Koichi Fukuhara：“块结晶对固态三嵌段低聚物 α-n-烷基-ω-n-alkoxvoligo(oxvethlene) 的构象的影响”，分子结构杂志 523(1-3)。 ）