Analysis of diffuse scattering in electron diffraction data for the crystal structure determination of Pigment Orange 13, C32H24Cl2N8O2. Issue 2 (1st March 2023)

• Record Type: Journal Article
• Authors: Gorelik, Tatiana E.; Bekő, Sàndor L.; Teteruk, Jaroslav; Heyse, Winfried; Schmidt, Martin U.
• Is Part Of: Acta crystallographica. Volume 79:Issue 2(2023)
• Page Start: 122
• Page End: 137
• Publication Date: 2023-03-01
• Subjects: 3D electron diffraction -- electron crystallography -- diffuse scattering -- stacking disorder -- lattice‐energy minimization
• DOI: 10.1107/S2052520623000720
• Languages: English
• ISSNs: 2052-5206

Abstract

Abstract : The crystal structure of the α phase of Pigment Orange 13, used until the end of 2013 to print the front covers of Acta Crystallographica Section C and inter alia, was solved by analysis of diffuse scattering in electron diffraction data. Abstract : 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.