Salbego Paulo R S, Orlando Tainára, Martins Marcos A P
Núcleo de Química de Heterociclos (NUQUIMHE), Department of Chemistry, Federal University of Santa Maria (UFSM) 97105-900 Santa Maria RS Brazil
RSC Adv. 2019 Sep 11;9(48):28195-28198. doi: 10.1039/c8ra07188h. eCollection 2019 Sep 3.
The study mentioned in the title of this comment article reports on two new polymorphic forms of 2-((2,6-dimethylphenyl)amino)benzoic acid, one with new X-ray diffraction data showing its crystal structure, and the other without. However, our investigation suggests that the newly reported crystal structure (Form II) is in fact the same structure previously reported (Form I), differing in how the structure refinement was performed. Herein, we demonstrated from the raw crystallographic data of Form I that both structures are the same, which invalidates the discovery of the new polymorph. In this comment article, we discuss point by point the findings reported by Long , as well as the fact that the report of the other polymorph (Form III) could present a broader investigation in order to assess its existence.
本评论文章标题中提及的研究报告了2-((2,6-二甲基苯基)氨基)苯甲酸的两种新多晶型形式，一种有显示其晶体结构的新X射线衍射数据，另一种则没有。然而，我们的研究表明，新报道的晶体结构（晶型II）实际上与先前报道的结构（晶型I）相同，只是在结构精修的方式上有所不同。在此，我们从晶型I的原始晶体学数据证明这两种结构是相同的，这使得新多晶型的发现无效。在本评论文章中，我们逐点讨论了Long报道的研究结果，以及另一种多晶型（晶型III）的报告可能需要进行更广泛研究以评估其存在的事实。
