溶液中の銅 (I) ビスフェナントロリンに対するMLCT興奮状態における超高速構造的再編成
George B Shaw1, Christian D Grant, Hideaki Shirota
1Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Journal of the American Chemical Society
|January 30, 2007
まとめ
この研究は,溶媒効果とは関係なく,光刺激中に銅複合体の超高速構造的平ら化を示しています. これらの発見は,興奮状態のダイナミクスを理解し,新しい太陽エネルギー材料の開発に不可欠です.
科学分野:
- フォトケミストリー フォトケミストリー
- 協調化化学について
- マテリアルサイエンス 材料科学
背景:
- 銅の複合体における金属からリガンドへの電荷移転 (MLCT) 移行は,電子構成の変更と幾何学的な再配置を伴う.
- 以前の研究では,MLCT状態の[Cu(I) ((dmp) ((2))) ((+)) のフランク・コンドン状態の平ら化と溶媒結合が示されました.
研究 の 目的:
- [Cu ((I)) ((dmp)) ((2))) ((+)) と[Cu ((I)) ((dpp)) ((2))) ((+)) の超高速興奮状態構造的ダイナミクスを調査する.
- MLCT移行中の一時的なスペクトル学的変化の構造的起源を解明する.
- 興奮状態ダイナミクスにおける溶媒特性の役割を理解する.
主な方法:
- 介電定数,粘度,熱拡散度が異なる溶剤における一時吸収スペクトロスコーピー.
- シングレット光ダイナミクスを測定するために,光向上変換スペクトロスコーピー.
- 構造的な洞察のための,レーザーで開始された時間解像度X線吸収スペクトロスコーピー (LITR-XAS).
主要な成果:
- 大きな振幅の幾何学的な動きにもかかわらず,溶媒に依存しない内部球のリラックスが観察されました.
- MLCT状態で超高速 (77 fs) の平ら化の過程を [Cu(I) ((dmp) ((2))) ((+)) で特定しました.
- シングレット光ダイナミクスは,フランク-コンドン幾何学における急速な非活性化経路を示唆する.
結論:
- 銅複合体のMLCT状態では,予期せぬ超高速の幾何学的平ら化が発生する.
- 内部球のリラックスが支配的なプロセスであり,溶媒の相互作用から大きく独立しています.
- 発見は,将来の超高速X線研究と太陽エネルギーアプリケーションのための銅複合体の設計を導く.
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