溶媒への超高速プロトン伝送:溶解と拡散制御の調節から得られる分子性と中間物質
J L Pérez-Lustres1, F Rodriguez-Prieto, M Mosquera
1Institute for Chemistry, Humboldt University of Berlin, Brook-Taylor-Strasse 2, 12489 Berlin, Germany.
Journal of the American Chemical Society
|April 10, 2007
まとめ
フォト誘発型陽子伝達 (PT) は溶解制御され,ダイナミクスは溶媒相互作用によって決定される. 単一の水分子の分子です.
科学分野:
- フォトケミストリーと物理化学
背景:
- 光誘発型陽子移転 (PT) は,化学と生物学における基本的なプロセスである.
- PTのダイナミクスを制御する要因を理解することは,さまざまなアプリケーションにとって非常に重要です.
研究 の 目的:
- 6‐ヒドロキシキノリニウム (6HQc) と6‐ヒドロキシ-1-メチルキノリニウム (6MQc) カチオンから水およびアルコールの光誘導型陽子伝達ダイナミクスを調査する.
- ズウィテリオン結合塩基1-メチルキノリニウム-6-オラート (6MQz) の溶解ダイナミクスを研究する.
主な方法:
- 静止および一時的吸収スペクトロスコーピー.
- 量子化学計算について.
- ソルバトクロミックプローブと溶解ダイナミクスのための介電損失データ.
主要な成果:
- ズウィテロニック6MQzは,分子内電子移転なしでの溶解動態をモニターします.
- 6HQcと6MQcカチオンからの陽子伝達 (PT) ダイナミクスは,溶解のダイナミクスを密接に追随し,溶解制御を示す.
- PTに対して2kJ/molの低活性化バリアが決定されました.
- 水では,6HQcと水分子の間の水素結合が複合体を安定させ,PTを容易にします.
- アセトニトリルでは,中間のPT状態が観察されました.
- 混合溶剤では,PTに続いて拡散制御反応が行われ,1つの水分子が陽子分離に十分である.
結論:
- 光誘導による陽子伝達は,主に溶解動力学によって制御される.
- 反応のメカニズムは,最初の水素結合と,その後の溶媒によるプロトンの分離を含みます.
- 単一の水分子の拡散は,陽子転送プロセスを駆動するのに十分です.
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