主鎖のボロン含有オリゴフェニレンは,9-H-9-ボラフッロレンのリング開きポリメリゼーションによる
Alexander Hübner1, Zheng-Wang Qu, Ulli Englert
1Institut für Anorganische und Analytische Chemie, Johann Wolfgang Goethe-Universität Frankfurt, Max-von-Laue-Strasse 7, D-60438 Frankfurt am Main, Germany.
Journal of the American Chemical Society
|March 4, 2011
まとめ
9-H-9-ボラフルオレン (5) は,in situ生成によってユニークな二元およびオリゴマーを形成する. これらの構造は,B-H-B結合とボロン橋渡しフェニル環を特徴として,NMRとX線結晶学によって特徴付けられています.
科学分野:
- 有機金属化学 有機金属化学
- ボロン化学 ボロン化学
- ポリマー化学のポリマー化学について
背景:
- 9-H-9-ボラフッロレン (5) は,9-Br-9-ボラフッロレンとEt(3) SiHからインシットで合成されます.
- 定位で生成された5は,標準反応条件下では,C(1) -対称ディマー (5)) を形成する.
研究 の 目的:
- 9-H-9-ボラフッロレンから形成されたダイマー (5) (((2) の構造を解明する.
- アダクト形成および水酸化反応におけるダイマー (5) (((2) の反応性を調査する.
- 9-H-9-ボラフローレンの長期的な安定性とオリゴメリゼーション経路を調査する.
主な方法:
- 9-H-9-ボラフローレンの局所生成.
- 反応のモニタリングと構造分析のためのNMRスペクトル (1H, 13C, 11B).
- 密度関数理論 (DFT) の計算で,同位体分析とメカニズム解明を行う.
- 主要な化合物の構造的特徴を明確にするために,X線結晶学.
- ダイマー,アダクト,オリゴーマーを含む反応産物の分離と特徴付け.
主要な成果:
- ダイマー (5) (((2) は,B-H-B 3センター,2電子結合とボロン橋渡しフェニル環を持つユニークな構造を有し,古典的なダイマーではありません.
- (5) (((2) は,ピリジンと清潔に反応してアダクト (5·py) を形成し,テルト-ブチラセチレンで水酸化され,製品9とその誘導体が得られます.
- 溶液中の (5) (((2) の長期不安定性により,リング開かれたジマー (例えば,10·py (((2)) とペンタマー (11),および関連するオリゴーマー (12,13) が形成されます.
- 回転するトロウエンの条件下で,サイクルジマー (14) が形成されます.
- 化合物9,10·py(2),11,12,13,および14は,X線結晶学で構造的に確認されました.
結論:
- この研究は,9-H-9-ボラフッロレンの複合的な構造と反応的振る舞いを明らかにし,その二分化とリング開きポリマー化への傾向を含む.
- DFT計算は,反応経路と構造的割り当てに関する包括的な理解を提供します.
- この発見は,9 - ボラフッ素のリング開きポリメリゼーションを制御するメカニズム的シナリオの洞察を提供します.
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