Combining insights from solid-state NMR and first principles calculation: applications to the 19F NMR of octafluoronaphthalene.
Combining insights from solid-state NMR and first principles calculation: applications to the 19F NMR of octafluoronaphthalene.
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结合固态 NMR 和第一原理计算的见解：在八氟萘 19F NMR 中的应用。
DOI：
10.1039/b701291h
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
P. Hodgkinson
中科院分区：
文献类型：
--
作者：
Andrew J. Robbins;William Ng;D. Jochym;T. Keal;S. Clark;D. Tozer;P. Hodgkinson
固体核磁共振方法学和计算化学的进展应用于固体八氟萘的（19）F核磁共振。实验证明，体磁化率（ABMS）的各向异性限制了魔角自旋谱的光谱分辨率，密度泛函理论（DFT）计算也证实了这一点。这导致了一个不寻常的观察结果，即随着样品被稀释，分辨率会提高。DFT计算提供了（19）F谱中每个峰的分配，但预测的准确性接近极限，来自二维核磁共振的相关信息在确认分配方面是非常宝贵的。本文还讨论了非高斯线形对使用二维核磁共振绘制光谱频率相关性的影响（例如，由于ABMS）。
Advances in solid-state NMR methodology and computational chemistry are applied to the (19)F NMR of solid octafluoronaphthalene. It is demonstrated experimentally, and confirmed by density functional theory (DFT) calculations, that the spectral resolution in the magic-angle spinning spectrum is limited by the anisotropy of the bulk magnetic susceptibility (ABMS). This leads to the unusual observation that the resolution improves as the sample is diluted. DFT calculations provide assignments of each of the peaks in the (19)F spectrum, but the predictions are close to the limits of accuracy and correlation information from 2-D NMR is invaluable in confirming the assignments. The effects of non-Gaussian lineshapes on the use of 2-D NMR for mapping correlations of spectral frequencies (e.g. due to the ABMS) are also discussed.