超高速な記憶喪失と,液体H2Oの水素結合ネットワークにおけるエネルギー再分配
M L Cowan1, B D Bruner, N Huse
1Department of Chemistry, University of Toronto, 80 St George Street, Toronto, Ontario, Canada M5S3H6.
Nature
|March 11, 2005
まとめ
研究者らは,高度な赤外線スペクトロスコピーを用いて,液体の水中の超高速水素結合ネットワークのダイナミクスを観察した. 液体の水は50フェムト秒で構造記憶を失い,エネルギーの急速な再分配を明らかにします.
科学分野:
- 物理化学 物理化学
- スペクトル顕微鏡検査です.
- マテリアルサイエンス 材料科学
背景:
- 液体の水のユニークな性質は,ダイナミックで3次元的な水素結合ネットワークから生じる.
- OHの伸縮振動の赤外線スペクトロスコピーは,水の構造的ダイナミクスを探査します.
- 以前の研究は,技術的な課題のため,H2O内のD2OまたはOD振動に限定されていました.
研究 の 目的:
- H2OでOHの伸縮振動を直接観察する.
- 超高速タイムスケールで水素結合ネットワークのダイナミクスを調査する.
- 液体の水におけるエネルギー再分配と構造記憶を理解する.
主な方法:
- H2O研究のために特別に設計された超薄サンプルセルを使用しました.
- 採用された多次元非線形赤外線スペクトロスコーピー.
- 完全に共鳴状態下でのOHの伸縮振動を分析した.
主要な成果:
- 観測された水素結合ネットワークのダイナミクスは,以前に報告されたよりも数桁も速い.
- OH周波数 (50 fs) で非常に速いスイープが検出されました.
- 水素結合サイトの初期不均一な分布の急速な消失が観察されました.
結論:
- 液体の水は,超高速な構造的動力学とエネルギー再分配を示す.
- 持続的な相関に関する水素結合ネットワークの記憶は50fs以内に失われます.
- この研究は,液体の水のフェムト秒ダイナミクスに関する前例のない洞察を提供します.
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