高級フルレレンのフォトイソメリゼーションの実験的証拠
Clemens Burda1, Anna C S Samia, David J Hathcock
1Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106, USA. burda@po.cwru.edu
Journal of the American Chemical Society
|October 17, 2002
まとめ
より大きなフルレンは,より遅い興奮状態のダイナミクスを示し,同位体数とストーン・ウェールズ同位体化メカニズムと相関する. これは,高速な光学ゲーティングアプリケーションの可能性を示唆しています.
科学分野:
- 物理化学 物理化学
- マテリアルサイエンス 材料科学
- フォトフィジックスの光学
背景:
- フーラーレン (C60,C70,C76,C84,C86,C90) は,ユニークな電子特性を有する炭素アロトロプである.
- 興奮状態のダイナミクスを理解することは,光電子学におけるその応用にとって極めて重要です.
- ストーン・ウェールズ・イソメリゼーション機構は,炭素ケージの構造変化を記述する.
研究 の 目的:
- 光刺激フラーレンの初期リラックスダイナミクスを調査する.
- フラーレンの大きさとイソメリゼーションとダイナミクスを相関させるため.
- 光学ゲーティングにおける潜在的な応用を探求するため.
主な方法:
- 分散のないフェムト秒ポンプ探査スペクトロスコーピー.
- 可視光線と近赤外線 (NIR) のスペクトル範囲におけるモニタリングダイナミクス.
- イソメリゼーション経路の計算分析.
主要な成果:
- 興奮状態の形成は,フルレンのサイズが大きくなると遅くなる.
- ダイナミクスは同位体数とストーン・ウェールズ機構と相関する.
- ストーン・ウェールズ・イソメリゼーションは,光誘導であり,障壁がない.
- 同位体エネルギーの違いは約1meVです.
- バック・アイソメリゼーションはピコ秒時間スケールで発生します.
- 広範な一時的な吸収が観察されました.
結論:
- フラーレンのサイズとイソメリズムは,興奮状態のリラックスに大きく影響する.
- フォト誘発ストーン・ウェールズ・イソメリゼーションが重要な要因である.
- 広範囲のトランジント吸収は,高速光学ゲート装置の可能性を示している.
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