超臨界二酸化炭素を用いた選択的自由基反応
Philip J Cormier1, Ryan M Clarke, Ryan M L McFadden
1Department of Chemistry and Biochemistry, Mount Allison University , 63C York Street, Sackville, New Brunswick E4L 1G8, Canada.
Journal of the American Chemical Society
|January 31, 2014
まとめ
研究者は,超臨界の二酸化炭素を用いてアルケンの反応性を修正した. この溶媒は非極性反応剤との反応を調節し,臨界点近くのエチレンとハロゲンアルケンの効果が異なる.
科学分野:
- 物理化学 物理化学について
- 化学動力学 化学動力学
- 超臨界流体 超臨界流体
背景:
- アルケンは,さまざまな反応性を持つ基本的な有機分子です.
- 二酸化炭素のような超臨界流体には,ユニークな溶媒特性があります.
- 反応選択性を制御することは,化学合成において極めて重要です.
研究 の 目的:
- 超臨界の二酸化炭素 (scCO2) でアルケンの反応性の変化を調査する.
- 非極性フリーラジカルとのアルケンの反応の選択性を,臨界に近い条件下で調査する.
- scCO2における異なるアルケンの運動行動を比較する.
主な方法:
- アルケーンにムオニウム (軽量の水素同位体) の自由基添加の測定速度定数.
- エチレン,ビニリデンフッ化物,ビニリデン塩化物を研究した.
- 臨界点に近い様々な圧力と温度で超臨界の二酸化炭素で実験を行った.
主要な成果:
- scCO2の臨界点近くのエチレンへのミューオニウム添加の臨界加速が観察されました.
- ハロゲン化アルケーン (ビニリデン・フッ化物およびビニリデン・塩化物) にムオニウム添加の臨界減速が観察されました.
- 反応速度の圧力と温度による依存性を実証した.
結論:
- 超臨界二酸化炭素は,アルケンの反応性と選択性を大幅に調整することができます.
- 臨界点近くの溶媒効果は,非ハロゲン酸アルケンとハロゲン酸アルケンの間で異なります.
- scCO2は,臨界に近い条件下でアルケンの化学を制御するための調節可能な媒介を提供します.
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