フォトクロミックルテニウム硫酸化物複合体の興奮状態歪曲
Beth Anne McClure1, Eric R Abrams, Jeffrey J Rack
1Department of Chemistry and Biochemistry, Nanoscale and Quantum Phenomena Institute, Ohio University, Athens, Ohio 45701, USA.
Journal of the American Chemical Society
|March 31, 2010
まとめ
フォトクロミックなルテニウム硫酸化物複合体は,S結合とO結合状態の間の光誘発性イソメリゼーションを経験する. 硫黄の置換物質の影響を受けたこの可逆的なプロセスは,異なる量子収量と時間尺度を持つ非アディアバティックなメカニズムを通じて発生します.
科学分野:
- 協調化化学について
- フォトケミストリー フォトケミストリー
- マテリアルサイエンス 材料科学
背景:
- フォトクロミックな材料は,光に曝露すると,可逆的な色変化を示します.
- ルテニウム複合体は,その多様な光物理的性質で知られている.
- 硫酸酸化リガンドは,ユニークな調整モードと反応性を備えています.
研究 の 目的:
- 新規の光染色ルテニウム硫酸化物複合体を合成し,特徴づけること.
- これらの複合体における光誘発性イソメリゼーションのメカニズムを調査する.
- 代用電子効果がフォトクロミック行動に及ぼす影響を調査する.
主な方法:
- ビピリジンと硫黄酸化リガンドを含むルテニウム (II) 複合体の合成と特徴付け.
- 電子トランジションを研究するためのUV-Vis吸収および放射スペクトロスコーピー.
- 興奮状態のダイナミクスを探査するために,フェムト秒の一時吸収スペクトロスコーピーを用いる.
- レドックス特性を評価するための電気化学測定.
主要な成果:
- 異なる硫酸化リガンド (OSOBn,OSONap,OSOBnF) を含む[Ru(bpy) ((2) ((OSOR) ] ((+) 複合体の合成に成功した.
- S-結合からO-結合のスルフォキシドの協調から,電荷移転刺激による光誘発性異体化が実証された.
- メタノールにおける可逆性イソメリゼーションを観測し,S結合イソメールへの熱的逆転を観測した.
- 硫黄の置換物によって影響される量子収量 (Phi{\s-->o}) と同化時間常数 (tau{\s-->o}) を決定する.
- 顕微鏡データは,特定の振動モードを含む,グラウンド状態と興奮状態の間の重要な歪みを示した.
結論:
- 合成されたルテニウム硫酸化物複合体は,効率的な光色化を示す.
- イソメリゼーションは,リラックスした (3) MLCT状態から非アディアバティックなメカニズムで進行します.
- 硫黄に対する置換作用は,S結合イソメアの性質を調節する.
- 低周波振動モードは,イソメリゼーション経路において重要な役割を果たします.
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