抗芳香性サイクロファンの3次元芳香性の決定要因
Hiroyuki Kawashima1, Shusaku Ukai1, Ryo Nozawa1
1Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan.
Journal of the American Chemical Society
|June 25, 2021
まとめ
研究者は2つの反芳香ニッケル (II) ノルコルロール単位で新しいサイクロファンを合成した. この構造は独特の対面の積み重ねを示し,3次元のアロマティック性とノルロール単位間の強い魅力的な相互作用をもたらします.
科学分野:
- 超分子化学
- 有機化学
- 材料科学
背景:
- 三次元アロマティック性は,π結合系における関心の分野である.
- ノルコロールなどの抗芳香マクロサイクルにはユニークな電子特性があります.
- サイクロファンの構造は,積み重ねられたマクロサイクル単位間の相互作用の研究を可能にします.
研究 の 目的:
- 2つの反芳香のNi (II) ノルコロール単位からなるサイクロファンを合成し,特徴づけること.
- ノルコロールサイクロファンの固体構造と積み重ねを調査する.
- この新しいシステムにおける3次元アロマティック性の現象を調査し,それをアロマティック・アナログと比較する.
主な方法:
- Ni (II) ノルコルロールとポルフィリンサイクロファンの合成.
- 固体構造とポリモルフィズムを決定するX線結晶学
- 電子特性および芳香性を分析するための光譜および計算方法 (例えば,NMR,DFT)
- 分子間の相互作用を定量化するために熱力学的測定とエネルギー分解分析を行う.
主要な成果:
- ノルコルロールサイクロファンが合成され,三つの固体構造を持つ結晶ポリモルフィズムを示した.
- 一つのポリモルフは3Dアロマティック性を示す,近いπ-π距離 (3.258 Å) の対面スタッキングを採用した.
- 実験的および理論的証拠 (小さな結合長交代,二酸化環電流) は,並べられたノルコロールスタックにおける3D芳香性を支持した.
- アナログのポルフィリンサイクロファンは,個々のポルフィリン芳香度に大きな変化なしに,スライドスタッキング (2.9 Å 位移,3.402 Å 距離) を示した.
- 溶液では,ノルコロールサイクロファンは,軌道が重複し,スタックされた状態とスタックされていない状態のバランスを示した.
- 熱力学的分析により,ノルコロール単位間の強い魅力的な相互作用が明らかになった.
結論:
- この研究は,反芳香のNi (II) ノルコル単位から構成されたサイクロファンの3次元芳香性の形成を証明している.
- 一つのポリモルフに並べられた対面スタッキングは 典型的な排斥期待に挑戦する重要な発見です
- ノルコルロール単位間の有意な魅力的な相互作用は,観察された積み重ね行動を駆動し,3Dの芳香性に寄与する.
- ポルフィリンアナログとの比較は,スタックされた構成におけるアンチアロマティックシステムの独特の電子的および構造的性質を強調する.
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