Mollica Giulia, Dekhil Myriam, Ziarelli Fabio, Thureau Pierre, Viel Stéphane
Aix-Marseille Université, CNRS, ICR UMR 7273, 13397 Marseille, France.
Aix-Marseille Université, Centrale Marseille, CNRS, Fédération des sciences chimiques de Marseille FR 1739, 13397 Marseille, France.
Solid State Nucl Magn Reson. 2015 Feb;65:114-21. doi: 10.1016/j.ssnmr.2014.12.003. Epub 2014 Dec 16.
The relationship between the crystal packing of powder samples and long-range (13)C-(13)C homonuclear dipolar couplings is presented and illustrated for the case of uniformly (13)C-enriched L-alanine and L-histidine·HCl·H2O. Dipolar coupling measurement is based on the partial reintroduction of dipolar interactions by spinning the sample slightly off-magic-angle, while the coupling of interest for a given spin pair is isolated with a frequency-selective pulse. A cost function is used to correlate the so-derived dipolar couplings to trial crystal structures of the samples under study. This procedure allowed for the investigation of the l-alanine space group and L-histidine·HCl·H2O space group and unit-cell parameters.
本文给出并说明了粉末样品的晶体堆积与长程（13）C-（13）C 同核偶极耦合之间的关系，以均匀（13）C 富集的 L-丙氨酸和 L-组氨酸·HCl·H2O 为例。偶极耦合测量基于通过将样品微偏离魔角旋转来部分重新引入偶极相互作用，而给定自旋对的感兴趣耦合则通过频率选择性脉冲进行分离。使用成本函数将由此得出的偶极耦合与所研究样品的试验晶体结构相关联。该程序允许对 L-丙氨酸空间群和 L-组氨酸·HCl·H2O 空间群以及晶胞参数进行研究。
