クロロフォーム-d中のサイクロヘキセン-1,2-ジカルボキシラートモノアニオンにおける水素結合対称性の変数温度研究
Charles L Perrin1, Kathryn D Burke
1Department of Chemistry, University of California-San Diego , La Jolla, California 92093-0358, United States.
Journal of the American Chemical Society
|February 18, 2014
まとめ
サイクロヘキセン-1,2-デカルボキシ酸モノアニオンにおける水素結合の対称性を研究した. 結果は,それが単一の対称的な構造ではなく,急速に相互変換するタウトマーの混合物として存在することを示しています.
科学分野:
- 有機化学 オーガニック・ケミストリー
- 物理化学 物理化学について
- スペクトロスコーピーは,スペクトロスコーピーを用います.
背景:
- 水素結合の対称性を理解することは,化学結合において極めて重要です.
- サイクロヘキセン-1,2-デカルボキシラートモノアニオンは,タウトメリズムを研究するためのモデルシステムを提示します.
研究 の 目的:
- 水素サイクロヘキセン-1,2-デカルボキシラートモノアニオンにおける水素結合の対称性を決定する.
- 同位体波乱効果の温度に依存する振る舞いを調査する.
主な方法:
- 核磁共振 (NMR) スペクトロスコピーを用いた.
- 酸素-18 ((18) O) を用いた同位体混乱は,化学的シフトを調査するために利用されました.
- クロロフォームで実験を行った.
主要な成果:
- 温度下降により,カルボキシル炭素とイプソ炭素の両方の (18) O誘発 (13) C化学シフト分離が増加しました.
- 観測されたイプソ炭素の増加は,カルボキシル酸の酸性に対する (18) O同位体の効果と一致しています.
結論:
- サイクロヘキセン-1,2-デカルボキシラートモノアニオンは,急速な均衡状態にあるタウトメアの混合物として存在します.
- 観測された温度依存は,特定の振動結合メカニズムを持つ単一の対称構造と矛盾しています.
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