Ulm University, Central Facility of Electron Microscopy, Materials Science Electron Microscopy, Albert Einstein Allee 11, 89069 Ulm, Germany.
Goethe University, Institute of Inorganic and Analytical Chemistry, Max-von-Laue-Str. 7, 60438 Frankfurt am Main, Germany.
Acta Crystallogr B Struct Sci Cryst Eng Mater. 2023 Apr 1;79(Pt 2):122-137. doi: 10.1107/S2052520623000720. Epub 2023 Feb 24.
The crystallographic study of two polymorphs of the industrial pyrazolone Pigment Orange 13 (P.O.13) is reported. The crystal structure of the β phase was determined using single-crystal X-ray analysis of a tiny needle. The α phase was investigated using three-dimensional electron diffraction. The electron diffraction data contain sharp Bragg reflections and strong diffuse streaks, associated with severe stacking disorder. The structure was solved by careful analysis of the diffuse scattering, and similarities of the unit-cell parameters with the β phase. The structure solution is described in detail and this provides a didactic example of solving molecular crystal structures in the presence of diffuse scattering. Several structural models were constructed and optimized by lattice-energy minimization with dispersion-corrected DFT. A four-layer model was found, which matches the electron diffraction data, including the diffuse scattering, and agrees with X-ray powder data. Additionally, five further phases of P.O.13 are described.
报道了工业吡唑酮颜料橙 13（P.O.13）两种多晶型物的晶体学研究。使用单晶 X 射线分析对β 相的微小针进行了晶体结构的确定。使用三维电子衍射研究了α相。电子衍射数据包含尖锐的布拉格反射和强烈的漫散射条纹，这与严重的堆积无序有关。通过仔细分析漫散射，以及与β相的单元参数的相似性，解决了结构问题。详细描述了结构解决方案，这为在存在漫散射的情况下解决分子晶体结构提供了一个教学范例。通过使用具有色散校正的 DFT 的晶格能最小化，构建并优化了几个结构模型。发现了一个四层模型，该模型与电子衍射数据（包括漫散射）匹配，并与 X 射线粉末数据一致。此外，还描述了 P.O.13 的另外五个相。
