電子は冷凍ガラスの中の有機分子を通ってトンネルを掘る
Oliver S Wenger1, Brian S Leigh, Randy M Villahermosa
1Beckman Institute, California Institute of Technology, Pasadena, CA 91125, USA.
Science (New York, N.Y.)
|January 8, 2005
まとめ
溶媒分子を通る電子トンネリングは,共電性結合のブリッジを通るよりも著しく遅い. この研究は,結合経路がタンパク質内の電子の流れを助けることを確認しています.
科学分野:
- 物理化学 物理化学
- 材料科学 材料科学とは
- バイオフィジックス 生物物理学
背景:
- 電子トンネリングは,生物学的および化学的なシステムにとって極めて重要な量子力学的プロセスである.
- 異なる媒体を介して電子伝送速度を理解することは,新しい電子材料の設計と生物学的エネルギー伝送の理解の鍵です.
研究 の 目的:
- 冷凍有機ガラスを経由する電子トンネリング速度を,共振結合分子ブリッジと比較して実験的に決定し,比較する.
- 透過結合経路と比較して,溶媒で分離された分子を介して電子輸送の効率を調査する.
主な方法:
- 電子トンネリング速度を定量化するために,ドナー発光滅測定を用いた.
- 溶媒介によるトンネル掘削のモデルシステムとして冷凍トロウレンと2メチルテトラヒドロフランガラスを使用した.
- 実験的な腐敗定数と,キシリルおよびアルキルブリッジのトンネル掘削で得られた定数を比較した.
主要な成果:
- 電子トンネリング分解定数は,トルーエンの1.23 Å−1 (1.4 eVバリア) と,2-メチルテトラヒドロフランの1.62 Å−1 (2.6 eVバリア) である.
- ヴァン・デル・ワールスの接触における溶媒分子間のトンネリングは,比較可能な共性結合ブリッジを通過するよりも20〜50倍遅いことが観察されました.
- 溶剤媒介型経路と経由結合経路の電子伝送効率の有意な差異を確立した.
結論:
- 協和結合構造は,溶媒で分離された分子と比較して,電子トンネリングのためのはるかに効率的な経路を提供します.
- これらの発見は,電子の流れを促進するコヴァラント結合経路の役割を実験的に検証し,特に折りたたまれたポリペプチド構造における電子伝送に関連しています.
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