NMR結晶学の新しいツール:DNP強化の固体NMRを用いた自然同位体豊富な有機分子の完全 (13) C/(15) N割り当て
Katharina Märker1,2, Morgane Pingret1,2, Jean-Marie Mouesca1,2
1Univ. Grenoble Alpes, INAC , F-38000 Grenoble, France.
Journal of the American Chemical Society
|October 21, 2015
まとめ
この研究は,有機分子における炭素-13と窒素-15の共振を自然同位体豊富で割り当てるための新しい核磁共振 (NMR) 相関実験を導入する. この進歩は,NMR結晶学を簡素化し,固体NMRでの正確な距離測定を可能にします.
科学分野:
- 固体核磁共振 (NMR) スペクトロシー
- クリスタルグラフィー
- 有機化学
背景:
- 自然同位体豊富度 (NA) の有機分子によるNMR結晶は,通常,実験的および計算されたNMR化学シフトを比較する必要があります.
- 限られた陽子 (1H) の解像度と,計算補助なしで炭素-13 (13C) と窒素-15 (15N) の共振を割り当てるという課題は,広範な適用を妨げています.
- 現在の方法は,しばしば構造に基づく化学シフト計算に依存し,デノボの割り当てを制限します.
研究 の 目的:
- 自然な同位体量での有機分子に対するNMR共振の割り当てにおける制限を克服する.
- 関連スペクトロスコーピーを用いた完全な de novo 13C と 15N の共振配分のための新しい方法を提示する.
- 1Hの割り当てを簡素化し,固体 NMR 距離測定を可能にするこの方法の有用性を実証する.
主な方法:
- ダイナミックな核極化 (DNP) 強化核磁共振 (NMR) スペクトロスコーピーを利用する.
- 13C-13Cと15N-13Cの相関実験を初めて行いました
- 非対称なユニット細胞に2つの分子を持つ自己組み立ての2'-デオキシグアノシン誘導体のde novo共振割り当てのためのこれらの方法を適用する.
主要な成果:
- 自然同位体豊富度 (NA) で完全なde novo 13Cと15N共振割り当てを達成した.
- DNPで強化された13C-13Cと15N-13Cの相関実験の有効性を実証した.
- この配分戦略は,後の1H配分を簡素化し,固体 NMR 距離測定に不可欠であることを示した.
結論:
- DNP強化の15N-13Cおよび13C相関スペクトルに基づく新しい代入戦略が提示されています.
- この方法は,13Cと15Nの割り当てのための計算式化学シフト計算の必要性を克服します.
- このアプローチは,1Hの割り当てを容易にし,固体NMRでの距離測定を可能にすることで,NMR結晶学を大幅に進歩させる.
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