オリゴメリックフローレノンおよびp-フェニルエチニレンブリッジを持つドナー・ブリッジ・アクセプター分子におけるスピン選択的電荷伝送経路の温度依存性
Amy M Scott1, Michael R Wasielewski
1Department of Chemistry and Argonne-Northwestern Solar Energy Research (ANSER) Center, Northwestern University, Evanston, Illinois 60208-3113, USA.
Journal of the American Chemical Society
|February 16, 2011
まとめ
ドナー・ブリッジ・アクセプター分子における電荷再結合の調査は,温度に依存する経路を明らかにしています. トルション運動はシングレット再結合に影響を及ぼし,トリプレット再結合は正の活性化エネルギー障壁を示します.
科学分野:
- フォトケミストリー フォトケミストリー
- 分子ダイナミクス 分子ダイナミクス
- 電子移転による電子の移転.
背景:
- ドナー・ブリッジ・アクセプター分子は,電荷再結合ダイナミクスを理解する上で極めて重要です.
- スピン選択的電荷再結合は,分子構造と温度によって影響を受けます.
- ラジカル・ペア・インターシステム・クロス (RP-ISC) は,スピン・ダイナミクスにおいて重要な役割を果たします.
研究 の 目的:
- スピン選択的分子内電荷再結合 (CR) の温度依存性を調査する.
- CR経路における異なる分子ブリッジ (フローレノンおよびp-フェニルエチニレン) の役割を解明する.
- シングレットとトリプルレットCR経路の活性化エネルギーとバリアを決定する.
主な方法:
- ナノ秒間断吸収スペクトロスコーピーを用いた.
- 実験は静的な磁場の存在下で行われました.
- 速度定数 (k ((CR), k ((CRS), k ((CRT), k ((ST)) を抽出するために,運動分析を使用した.
主要な成果:
- 300 Kのp-フェニルエチニレンブリッジのCR経路のクロスオーバーが観察されました.
- フロレノンブリッジによるシングレットCRは,トルション運動による負の活性化エネルギーを示した.
- すべての橋を通る三重のCR経路は,1100cmから4500cmまでの障壁で,正の活性化エネルギーを示した.
結論:
- この研究は,スピン選択型CRの複雑な温度依存性を強調しています.
- 分子ブリッジは,CR経路とその温度依存性を著しく調節する.
- 半古典的な電子伝送理論は,トルション運動の観測された活性化障壁をモデル化することができます.
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