リニウムの興奮状態の切り替え (I) ドナー-ドナーとドナー-受容体置換体によるビピリジル複合体
Joshua J Sutton1,2, Dan Preston1,2, Philipp Traber3
1Department of Chemistry, University of Otago, Dunedin 9016, New Zealand.
Journal of the American Chemical Society
|June 11, 2021
まとめ
この研究は,トリフェニラミン (TPA) とベンゾチアディアゾール (BTD) リガンドを持つレニウム複合体の光学特性を示しています. メタルからリガンドへの電荷移転 (MLCT) またはリガンド内での電荷移転 (ILCT) のいずれかの溶媒依存の興奮状態が観察されました.
科学分野:
- 写真化学
- 協調化学
- スペクトロスコーピー
背景:
- レーニウム (I) ポリピリドール複合体は,その光物理的性質のために広く研究されている.
- 調節リガンド置換剤は,電荷移転特性と興奮状態の行動に影響を与える.
- 溶媒の効果を理解することは,光物理学的プロセスを制御するために不可欠です.
研究 の 目的:
- ReTPA2 と ReTPA-BTD の2つのレニウム (I) 複合体の光学および興奮状態の性質を調査する.
- 興奮状態の性質 (MLCT vs. ILCT) とその溶媒依存性を解明する.
- 溶媒制御された電荷移転スイッチングにおけるスピン軌道結合の役割を探求する.
主な方法:
- UV-Vis吸収と放射スペクトル
- 共振ラーマン光譜法
- 時間解像度の赤外線スペクトル
- 密度関数理論 (DFT) と時間依存型DFT (TDDFT) の計算
主要な成果:
- ReTPA2は460 nmで少量のソルバトクロミズムで強い内結合電荷伝送帯 (ILCT) を表している.
- ReTPA-BTDは,TPA → bpyとして割り当てられた,より弱いILCT移行を示しています.
- 両複合体には2つの放出状態が観察され,その強度は溶媒によって調節された.
- 時間解像度IRスペクトロスコピーは,CH2Cl2におけるMLCT状態とMeCNにおけるILCT状態を明らかにした.
- DFT計算は,スピン軌道結合による電荷移転状態の溶媒誘発の切り替えを確認した.
結論:
- ReTPA2とReTPA-BTDの光学特性と興奮状態のダイナミクスは,リガンド置換と溶媒の極性によって著しく影響を受けます.
- 溶媒の極性は,スピン軌道結合の調節によって興奮状態 (MLCT vs. ILCT) の性質を決定する.
- この研究は,合理的な溶媒選択によってレニウム複合体の電荷移転状態を制御するための戦略を示しています.
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