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ビカルボネートとアルキルカルボネートラジカル:構造的整合性と脂質成分との反応
Michael Bühl1, Peter DaBell1, David W Manley1
1University of St. Andrews , EaStCHEM School of Chemistry, St. Andrews, Fife KY16 9ST, United Kingdom.
Journal of the American Chemical Society
|December 2, 2015
まとめ
酸塩化学の重要な分子である二酸化炭素基は,メチル炭酸基として実験的に研究されている. この研究は,放射性化学を理解するための意味を持つ,最も強いカルボキシル酸であることを明らかにしています.
科学分野:
- 化学運動学
- コンピュータ化学
- フリーラジカル化学
背景:
- 炭酸根 (HCO3•) と炭酸根アニオン (CO3•−) は酸/結合塩基のペアを形成する.
- バイカーボネート基の反応性と性質を理解することは,様々な化学プロセスにとって極めて重要です.
研究 の 目的:
- 二酸化炭素のモデルとしてメチル炭酸根の性質を実験的に調査する.
- ビカルボネート基の解離パラメータと酸度を計算的に決定する.
- メチル炭酸ラジカルと脂質成分の反応メカニズムを解明する.
主な方法:
- メチル炭酸原素を生成するオキシム炭酸原素のUV照射.
- 速度定数およびアレニウスパラメータを測定するための運動電子パラマグネティック共振 (EPR) スペクトロスコーピー.
- 熱力学および活性化パラメータの密度関数理論 (DFT) 計算 (CAM-B3LYPレベル) とpKa予測.
主要な成果:
- メチル炭酸ラジカルはオレートやコレステロールなどの脂質に二重結合を加える.
- バイアリック位置からの水素原子抽出は,リノレートとリノレナートでの添加と競合する.
- DFTの計算は,ガスと非極性溶媒のバイカーボネート基の実質的な寿命を予測しています.
- DFT分析では,バイカーボネートラジカルのpKaが約-2であることを示し,最も強いカルボキシル酸であることが判明した.
結論:
- バイカーボネート基は,他の活性酸素種 (ROS) に比べてユニークな反応性を表しています.
- ビカルボネートラジカルは様々な環境で重要な安定性を持っています.
- この研究は,バイカーボネートラジカルを非常に強い炭酸として確立し,既知の酸塩化学の分野を広げています.
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