分子液体の穴と,水嫌性溶解性の理論
1Department of Chemistry, University of California, Berkeley 94720, USA.
Journal of the American Chemical Society
|January 1, 1990
まとめ
この研究は,液体の水は液体の水であることを明らかにしています.
科学分野:
- 物理化学 物理化学
- コンピューティング・ケミストリー
- 溶解科学とは,溶解科学である.
背景:
- 溶質の行動に対する溶媒の効果を理解することは,化学において極めて重要です.
- 水と有機溶媒の溶解の違いは,しばしば水のユニークな水素結合構造に起因する.
- 別の仮説は,分子サイズがより重要な役割を果たすことを示唆しています.
研究 の 目的:
- 様々な分子溶媒における原子サイズの空洞の形成の働きを調査する.
- 水素結合ではなく分子サイズが,主に水と非水性溶媒の溶解量差を説明するという仮説を検証する.
- 液体の水の自由体積特性を硬球溶媒と比較する.
主な方法:
- 清潔な液体の熱構成データを使用した.
- 原子サイズの硬い球状の穴の形成作業を計算した.
- 液体水における惰性ガスの溶解性を予測するためにスケール粒子モデルを使用した.
主要な成果:
- 液体の水は,より高い自由分数体積を示しますが,有機溶媒と比較してより小さなポケットに分布しています.
- 水中の穴形成作業は,比較可能な有機溶媒の穴形成作業と大きく異なる.
- スケールした粒子のモデルは,TIP4Pの水中の空洞作業を原子サイズの空洞で約20%過小評価した.
結論:
- 水素結合だけでなく,自由体積分布の構造的差異は,水中の溶解を理解するための鍵です.
- 水の分子サイズが小さいため,大分子溶媒と比較して,惰性ガスの空洞形成は好ましくありません.
- 液体構造の文脈において,原子サイズの空洞はサブマクロスコープと考えられるべきである.
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