電子移転から[Ru(bpy) 32+とフェロセンの誘導体間のエネルギー移転へのpH駆動メカニズム
Claire Drolen1, Eric Conklin1, Stephen J Hetterich1
1Department of Chemistry , Amherst College , Merrill Science Building , Amherst , Massachusetts 01002 , United States.
Journal of the American Chemical Society
|August 3, 2018
まとめ
陽子の可用性は,ルテニウムトリス (ビピリジン) の興奮状態が水中のフェロセンの誘導体とどのように相互作用するかを決定する. 消火メカニズムは pH に基づいて エネルギーと電子の移転を切り替え 複雑な消火経路を明らかにします
科学分野:
- 写真化学
- 超分子化学
- 電気化学
背景:
- ルテニウムトリス (((ビピリジン)) ([Ru (((bpy) 3) 2+) 興奮状態は光化学において重要であり,エネルギーまたは電子の移転により無効化される.
- フェロセンの誘導体は,光物理学的研究で広く電子ドナーおよびクエンチャーとして使用されています.
- 刺激状態の無効化メカニズムを理解することは,効率的な光化学システムを設計する上で鍵となる.
研究 の 目的:
- 水溶液中のフェロセンの誘導体による[Ru(bpy) 3+の興奮状態の無活性化経路に対する陽子の利用可能性の影響を調査する.
- 速度定数を調節する要因を特定し,消火のメカニズムを明らかにする.
- エネルギーと電子伝送プロセスのpH制御されたスイッチングの可能性を探求する.
主な方法:
- スターン・ヴォルマー quenching 分析で quenching 速度定数を決定する.
- 興奮状態のダイナミクスを探すための一時的吸収スペクトロスコーピー.
- 機能化されたフェロセンの誘導体 (フェロセニル-アミジニウムとフェロセニル-トリメチルアモニウム) の合成と特徴付け
主要な成果:
- フェロセニルアミディニウム (Fc-am) による[Ru(bpy) ]2+の消火速定数は,フェロセニルトリメチルアモニウム (Fc-mam) の定数とは異なり,pHに依存していた.
- Fc-amの消火メカニズムにはpH依存のスイッチが検出されました.
- 低pH (プロトン化されたFc-am) では,エネルギー転送が支配的であり,高pH (プロトン化されたFc-am) では,電子転送が支配的になる.
- 観察された機械的なスイッチングは,単純な駆動力による議論で説明できません.
結論:
- フェロセンの誘導体に転移性陽子の存在または欠如は,[Ru(bpy) 3 2+の興奮状態の消火率を大幅に調節する.
- 溶液のpHは,特定のフェロセンの誘導体によって[Ru(bpy) 3+の非活性化メカニズム (エネルギー対電子転送) を制御的に切り替えることができる.
- 熱力学的駆動力以外の要因は,これらの双分子相互作用における興奮状態の無効化経路を決定する上で重要な役割を果たします.
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