双分子光誘導電子移転における閉殻および開殻金属複合体のケージ脱出率を制御する要因
Alexia Ripak1, Ana Karem Vega Salgado1, Danillo Valverde2
1Molecular Chemistry, Materials and Catalysis (MOST), UCLouvain, Institut de la Matière Condensée et des Nanosciences (IMCN), Place Louis Pasteur 1/L4.01.02, B-1348 Louvain-la-Neuve, Belgium.
Journal of the American Chemical Society
|July 30, 2024
まとめ
光敏感剤のケージ脱出率は11種類の溶媒で研究された. イリジウム (III) 複合体は,光レドックス触媒における潜在能力を示唆し,鉄 (III) 複合体は,光レドックス触媒における潜在能力を示唆した.
科学分野:
- 光化学と光物理学
- キャタリシス
- 物理化学
背景:
- 効率的な光触媒の開発には 興奮状態の電子移転を理解することが重要です
- ゲミナート・ラジカル・ペアの再結合は反応結果に大きく影響する.
- 溶媒の効果は,電荷分離と再結合のダイナミクスを制御する上で重要な役割を果たします.
研究 の 目的:
- 異なる溶媒における様々な金属光敏感剤 (Fe (III),Ru (II),Ir (III)) のケージ脱出率を調査する.
- 光敏感剤の電子構造 (閉殻対開殻) と溶媒の介電特性によるケージ脱出率の影響を明らかにする.
- フォトレドックス触媒における光敏感剤の性能を最適化するためのガイドラインを提供すること.
主な方法:
- 6つの異なる光敏感剤 (Fe (III),Ru (II),Ir (III)) と電子ドナーとしてトライ-p-トライアミンを用いてケージ脱出率の実験研究.
- 溶媒の極性 (11つの溶媒) を系統的に変化させ,介電効果を検出する.
- スピンダイナミクス (システム間交差) と電荷再結合経路の分析
主要な成果:
- イリジウム (III) 光敏感剤は,最も高いケージ脱出率 (0. 67-1) を示し,フォトレドックス触媒の優れた可能性を示した.
- ルテニウム (Ruthenium) とオスミウム (Osmium) の光敏感剤は,適度から良好な収量を示した (それぞれ約0.65,0.38).
- 鉄 (III) 光敏感剤は,高圧電定数溶媒において低収量 (<0.1) を示したが,低圧電定数溶媒において有意に増加した (最大0.58),これは,閉殻複合体におけるスピン禁止再結合と,開殻複合体におけるスピン許容再結合に起因する.
結論:
- ケージ脱出率は,光敏感剤の電子構成と溶媒環境に大きく依存する.
- 閉じ殻の光敏感剤 (Ir(III,Ru(II)) は,スピン禁止再結合により,溶媒の介電効果から独立して高いケージ脱出効率を生成します.
- オープンシェル光敏感剤 (Fe ((III)) は,溶媒に依存する収量を示し,光還元触媒の低介電性媒体での反応性を調節する機会を提供します.
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