セルフ・アセンブリ・インテリアの外部要素への曝露. 運動的なアプローチです
1Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA. menger@emory.edu
Journal of the American Chemical Society
|July 20, 2006
まとめ
表面活性物質がミセルに吸収されることは,硫黄鎖の周期性酸化を著しく遅らせたが,過酸化水素酸化は遅らせなかった. これは,無秩序なミセルは,すべての鎖の位置に対してミセルの表面に同様のアクセスを提供することを示唆しています.
科学分野:
- 物理化学 物理化学
- 超分子化学 超分子化学
- 化学動力学 化学動力学
背景:
- 表面活性物質はミセルに自己組み立てられ,溶液中の組織化された構造を形成します.
- ミセル内の表面活性物質分子の異なる部分のアクセシビリティを理解することは,それらの反応性を予測するために重要である.
研究 の 目的:
- チオエーテルを含むカチオンの表面活性剤の酸化速度に対するミセル形成の影響を調査する.
- 表面活性物質の鎖内の硫黄原子の位置が,ミセル内の酸化物質へのアクセシビリティに影響するかどうかを決定する.
主な方法:
- 硫黄の位置が異なるカチオンの表面活性物質をナトリウムドデシル硫酸ミセルに吸収する.
- 酸化剤としてペリオデートと過酸化水素を用いたチオエーテル酸化の運動分析.
- 反応速度を決定するための核磁共鳴 (NMR) スペクトロスコーピー.
主要な成果:
- 周期性酸化率は,硫黄原子の位置に関係なく,ミセライゼーションで2桁減少した.
- 酸化過酸化水素の酸化率は,ミセル形成によってほとんど影響を受けませんでした.
- 表面活性剤の鎖内の硫黄の位置に対する酸化速度の有意な依存性は,いずれの酸化剤でも観察されなかった.
結論:
- ミセルの形成は,すべての鎖の位置が外部環境に対して同様のアクセシビリティを示す乱雑な構造につながります.
- NMRを用いた動的方法は,自己組み立てやポリマーシステム内の分子のアクセシビリティを調査するための実行可能なアプローチです.
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