高度に定義されたペリレンビシミド四重 π スタックにおける超高速エクシトンの移転,局所化,およびエクシマー形成の動態
Christina Kaufmann1, Woojae Kim2, Agnieszka Nowak-Król1
1Universität Würzburg , Institut für Organische Chemie & Center for Nanosystems Chemistry , Am Hubland , 97074 Würzburg , Germany.
Journal of the American Chemical Society
|March 6, 2018
まとめ
新しいペリレンビシミド (PBI) ダイマー,Bis-PBIは4つの染色体スタックに自己組み立てられます. 超高速ダイナミクスは,エキシトンの連動性の急速な喪失とエクシマー状態へのリラックスを示します.
科学分野:
- 超分子化学
- フォト物理学
- 有機材料
背景:
- ペリレンビシミド (PBIs) は,調節可能な光物理的性質を持つ多機能色素である.
- PBIデリバティブの自己組み立ては,高度な有機材料の開発に不可欠です.
- PBIの集積物におけるエクシトンダイナミクスを理解することは,エネルギー転送と光採集プロセスを制御する上で鍵となる.
研究 の 目的:
- ベイ・テッダーされたペリレン・ビシミド (PBI) ダイマー,Bis-PBIを合成し,特徴づけること.
- Bis-PBIの自己組み立て行動と集合構造を調査する.
- 自ら組み立てられたBis-PBI四重スタックの超高速エクシトンダイナミクスとリラクゼーション経路を解明する.
主な方法:
- Bis-PBI合成のためのPd/Cu触媒化されたグラザー型酸化ホモカップリング.
- 静止状態の吸収と放出スペクトロスコーピーは,光学特性を特徴づけます.
- ブロードバンド光アップコンバージョンスペクトロスコーピー (FLUPS) と一時吸収スペクトロスコーピーは,興奮状態のダイナミクスを研究します.
主要な成果:
- ビス-PBIジメルは合成され,高結合定数 (10^6 M^-1まで) の4つの染色体の離散型π-スタックに自己組み立てられる.
- スペクトルシグネチャーは H型エキシトニクカップリングを 四重のスタックで示しています
- FLUPSは,変位したフレンケルエキストン状態からエクシマー状態への超高速なコヒーレンス喪失 (τ ≈ 200 fs) を明らかにする.
- 短四重のスタックで観察された一貫したエクシトン伝播とマルチエクシトン生成の欠如.
結論:
- 合成されたBis-PBI二酸化物は,明確に定義されたH-聚合物を形成する.
- エクシトンダイナミクスは,短縮された総長のため,快速なコヒーレンス喪失とエクシマー状態へのリラックスによって支配される.
- 四重のスタック構造は一貫したエクシトンの伝播を制限し,マルチエクシトンの生成を防ぐ.
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