Computation and NMR crystallography of terbutaline sulfate
Computation and NMR crystallography of terbutaline sulfate
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DOI：
10.1002/mrc.2636
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发表时间：
2010-12-01
影响因子：
2
通讯作者：
Stein, Robin S.
中科院分区：
文献类型：
--
作者：
Harris, Robin K.;Hodgkinson, Paul;Stein, Robin S.
本文通过计算和高级实验的方法，解决了核磁共振结晶学的关键挑战之一，即在晶体结构中指定特定位置的单个共振。此外，它还展示了如何使用核磁共振进行晶体结构验证。所检查的病例为特布他林硫酸盐B型。记录了CPMAS(13)C和FAST MAS(1)H谱，并尽可能地归属了这些峰。用CASTEP程序计算的(13)C化学位移与实验获得的结果进行比较(包括投影仪增宽波原理的量规)，可以比较结构的两种不同的单晶评估的准确性，并定位其中一种评估的错误。这些计算在指认(13)C和(1)H共振以及一系列二维(2D)谱(HETCOR、DQ-CRIMPS和质子-质子自旋扩散)方面都得到了实质性的帮助。2D光谱使许多质子的化学位移得以精确定位。因此，对于大多数(13)C峰和一些(1)H信号，已经建立了核磁共振位移与晶体结构中特定核位置的关系。重点讨论了氢键对质子化学位移的影响。版权所有(C)2010 John Wiley&Sons，Ltd.
This article addresses, by means of computation and advanced experiments, one of the key challenges of NMR crystallography, namely the assignment of individual resonances to specific sites in a crystal structure. Moreover, it shows how NMR can be used for crystal structure validation. The case examined is form B of terbutaline sulfate. CPMAS (13)C and fast MAS (1)H spectra have been recorded and the peaks assigned as far as possible. Comparison of (13)C chemical shifts computed using the CASTEP program (incorporating the Gauge Including Projector Augmented Wave principle) with those obtained experimentally enable the accuracy of the two distinct single-crystal evaluations of the structure to be compared and an error in one of these is located. The computations have substantiallly aided in the assignments of both (13)C and (1)H resonances, as has a series of two-dimensional (2D) spectra (HETCOR, DQ-CRAMPS and proton-proton spin diffusion). The 2D spectra have enabled many of the proton chemical shifts to be pinpointed. The relationships of the NMR shifts to the specific nuclear sites in the crystal structure have therefore been established for most (13)C peaks and for some (1)H signals. Emphasis is placed on the effects of hydrogen bonding on the proton chemical shifts. Copyright (C) 2010 John Wiley & Sons, Ltd.