モノディスパースマクロモレキュルのテンプレート指向合成におけるポジティブな協力性
Matthew E Belowich1, Cory Valente, Ronald A Smaldone
1Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3133, United States.
Journal of the American Chemical Society
|February 7, 2012
まとめ
合成されたオリゴロタキサンは,協力的な [π··π] スタッキング相互作用により,形成効率と剛性の向上を示します. これは,柔軟な類型と対照的に,超分子化学における新しい自己組み立て機構を強調しています.
科学分野:
- 超分子化学 超分子化学
- オーガニック・シンセシス オーガニック・シンセシス
- マテリアルサイエンス 材料科学
背景:
- テンプレート誘導合成は,オリゴロタキサンなどの複雑な分子構造の構築を可能にします.
- 特定の認識部位を持つオリゴロタキサンは,自己組織化して秩序ある構造を形成することができる.
- 形状と組立効率の制御は,新しい材料の設計に不可欠です.
研究 の 目的:
- 異なるスペーサー単位を持つ2連鎖のオリゴロタキサン (RとR') を合成し,特徴づけること.
- [π··π]の積み重ね相互作用が構造特性と組立効率に与える影響を調査する.
- テンプレート・ディレクテッド・セルフ・アセンブリにおけるポジティブ・コオペラティビティのメカニズムを解明する.
主な方法:
- 2,6-ピリジネジカルボックスアルデヒドとテトラエチレネグリコールビス (((2-アミノフェニル) エーテルを用いたテンプレート誘導合成.
- 高解像度質量スペクトロメトリー (HR-MS) と核磁共振 (NMR) スペクトロスコーピーを用いた特徴付け.
- イオン移動質量スペクトロメトリー (IM-MS) と分子力学の計算を用いた構成特性の分析.
主要な成果:
- トリスメチレンブリッジを備えたRシリーズのオリゴロタキサンは, [π···π]の積み重ねにより,固い棒のような形状を採用しました.
- R'シリーズのオリゴロタキサンは,p-フェニレンリンクヤーで,柔軟な形状を示した.
- Rシリーズは,著しく高い収穫率 (88-98%) と形成における積極的な協力性,特に高級オリゴロタキサンについて示した.
- スタッピングの安定化に起因するRシリーズのポジティブな協同性は,インミンボンドごとに形成効率を最大99.9%まで高めました.
- R'シリーズは,協同化なしでは,より速く,しかし,より低い収穫 (72-85%) を示しました.
結論:
- 拡張された [π··π] スタッキング相互作用は,オリゴロタキサンの固い棒のような形状を達成するための鍵です.
- ポジティブな協同性は,テンプレート主導の自己組み立てプロセスの効率と生産性を著しく高めます.
- Rシリーズは,柔軟なR'シリーズと対照的に,硬直で高効率の超分子構造のための成功した設計を表しています.
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