大型の多面体協調ケージの構造とダイナミックな行動:珍しいケージ対ケージの相互変換
Andrew Stephenson1, Stephen P Argent, Thomas Riis-Johannessen
1Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom.
Journal of the American Chemical Society
|December 24, 2010
まとめ
トランジション金属とバイバイデントのブリッジングリガンド (L) によって形成された新しい調整ケージは,新しい構造を示しています. カドミウム (Cd) 三角形のプリズマケージは,溶液中の安定した熱力学的産物であり,より大きなケージから数週間で形成されます.
科学分野:
- 協調化化学について
- 超分子化学 超分子化学
- マテリアルサイエンス 材料科学
背景:
- ブリッジリングリガンドを用いた多面体協調ケージの合成は,超分子化学の重要な分野である.
- リガンドL,{α,α-bis[3-(2-ピリジル) ピラゾール-1-イル]-1,4-ジメチルベンゼン}は,ピラゾリル-ピリジンの2つのケラリング単位を含み,複雑な構造の形成を可能にします.
- 以前の研究では,Ni (II) による8核の立方体ケージの形成が示されていた.
研究 の 目的:
- ビス-ビデンテートブリッジングリガンドLが様々な移行金属 (Cu(II),Zn(II),Cd(II)) と反応する過程を調査する.
- 新規の構造型に焦点を当てて,その結果生じた調整ケージの特徴を記述する.
- これらの調整ケージの溶液の安定性と形成経路を調査する.
主な方法:
- 移行金属ディケーション (Cu(II),Zn(II),Cd(II)) がリガンドLと2M:3Lの比率で反応する.
- X線結晶学を用いた結果の調整ケージの構造的特徴.
- 電気スプレー質量スペクトロメトリー (ES-MS) と1H NMRスペクトロスコーピーを用いて溶液の振る舞いの分析.
主要な成果:
- Ni(II) 複合体は8核の立方体ケージを形成し,以前の発見と一致しています.
- 新しい三角形のプリズマケージ [Cu(6) L(9) ]((BF(4)) ((12) は,Cu(II) で形成されました.
- 前例のないヘクサデカヌクレアケージ [M(16) L(24) ]X(32) が,歪んだテトラキャップの断片化されたテトラヘッドロンのコアで,Zn(II) とCd(II) に対して観察されました.
- 六核トライゴナルプリズマ [Cd(6) L(9) ]((BF(4)) ((12) は,溶液中のCd(II) の熱力学的産物として特定され,それは[Cd(16) L(24) ]のケージが数週間にわたって再配置されたことから形成された.
結論:
- ビスビデント酸のブリッジリングリガンドLは,異なる移行金属を持つ多様な多面体協調ケージに組み立てることができます.
- 三角形のプリズマケージは,より大きな六十核ケージの初期形成にもかかわらず,溶液中のCd (II) の熱力学的に好ましい製品です.
- この研究は,溶液中の調整ケージ形成と再配置のダイナミックな性質を強調しています.
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