S2状態におけるアセチラセトン (2,4-ペンタンダイオン) の超高速ダイナミクス
Lionel Poisson1, Pascale Roubin, Stéphane Coussan
1Laboratoire Francis Perrin (CNRS-URA-2453), DSM/IRAMIS/Service des Photons, Atomes et Molécules, C.E.A. Saclay, F-91191 Gif-sur-Yvette cedex, France.
Journal of the American Chemical Society
|February 20, 2008
まとめ
フェムト秒スペクトロスコーピーは,興奮したアセチラセトンのダイナミクスを明らかにしました. 重要な発見は,S2状態からS1状態への急速な移行であり,β-ダイケトンの行動を理解するために不可欠です.
科学分野:
- 物理化学 物理化学
- 分子ダイナミクス 分子ダイナミクス
- スペクトル顕微鏡検査です.
背景:
- アセチラセトンはエノール (E-AcAc) とケトの形態で存在します.
- 興奮状態のダイナミクスを理解することは,光化学にとって不可欠です.
研究 の 目的:
- アセチラセトン (E-AcAc) のエノリック形態のフェムト秒ダイナミクスを研究する.
- S2 と S1 の潜在エネルギー表面における興奮状態の進化を解明する.
主な方法:
- フェムト秒ポンプ・プローブスペクトロスコーピー.
- 266nmでの興奮は,S2 (pi,pi,pi) 状態になる.
- 800 nm マルチフォトンイオン化による探査.
主要な成果:
- システムは,70 +/- 10 fs. の範囲で興奮領域を離れました.
- 1.4 +/- 0.2 psの時間常数で,S2からS1状態への有意な移行が起こった.
- 分子内振動エネルギーリラックス (IVR) の証拠が観察されました.
結論:
- 興奮したE-AcAcの多段階の進化は,β-ダイケトン光物理学の洞察を提供します.
- IVRは,O-H結合からのエネルギーを他の分子モードに転送します.
- この研究は,他の活性化されたβ-二キトンの定性モデルを提供します.
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