特殊に歪んだペンタセネスの合成,構造,解像度
Jun Lu1, Douglas M Ho, Nancy J Vogelaar
1Department of Chemistry, Princeton University, Princeton, NJ 08544, USA.
Journal of the American Chemical Society
|December 21, 2006
まとめ
9,10,11,20,21,22-ヘキサフェニルテトラベンゾ[a,c,l,n]ペンタセン (2) とそのジメチル誘導体 (2m) を合成し,特徴づけました. これらの化合物は極端な回転と高い光学活性を示し,室温でゆっくりとレース化します.
科学分野:
- 有機化学 オーガニック・ケミストリー
- マテリアルサイエンス 材料科学
- 超分子化学 超分子化学
背景:
- ポリサイクル芳香炭化水素 (PAH) は,有機電子や材料科学における基本的な構成要素です.
- PAHsにおける高度な分子歪みを達成することは,その光物理的および電子的特性を調節するために,挑戦的でありながらも不可欠です.
- 歪んだPAHの構造-特性関係を理解すると,新しい機能的材料が生まれます.
研究 の 目的:
- 新型,高度に歪んだポリサイクル芳香炭化水素,特に9,10,11,20,21,22-ヘキサフェニルテトラベンゾ[a,c,l,n]ペンタセン (2) およびそのジメチル誘導体 (2m) を合成する.
- これらの合成化合物の構造的,光物理的,および光学的な性質を特徴づける.
- 種族化ダイナミクスを調査し,実験結果と計算による予測を比較する.
主な方法:
- 1,3-ディフェニルフェナントロ[9,10-c]フーランとビサリン等価素の反応による合成,次に脱酸素化.
- 歪んだ分子構造の詳細な構造的決定のためのX線結晶学.
- エナティオメア解像度および特定の回転の測定のためのキラル染色体.
- 変数温度ラセミゼーションの研究とコンピューティングモデリング.
主要な成果:
- 9,10,11,20,21,22-ヘキサフェニルテトラベンゾ[a,c,l,n]ペンタゼン (2) とそのダイメチル誘導体 (2m) の合成が成功し,それらは強いオレンジ色光を持つ明るい赤色の固体である.
- X線構造は,これらの化合物を,端から端まで144度まで曲がりくねった,最も高度に曲がった多環芳香炭化水素として知られています.
- 純粋なエナチオマーは,非常に高い特定の回転 ([alpha]D = 7400 度で 2, 5600 度で 2m) を表しますが,室温ではゆっくりとレース化されます (DeltaG++rac = 24 kcal/mol).
- 実験データは,幾何学と人種化障壁に関する計算研究とよく一致しています.
結論:
- この研究は,重要な構造的およびカイロプティカルな特性を有する,高度に歪んだPAHの新種を提示しています.
- 極端な回転と高い光学活動は,PAH設計の新たな境界を示しています.
- 観察されたラセミゼーションバリアは,これらの複雑な分子のダイナミックな行動に関する洞察を提供します.
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