Ab initio structure determination of nanocrystals of organic pharmaceutical compounds by electron diffraction at room temperature using a Timepix quantum area direct electron detector

作者：van Genderen E; Clabbers M T B; Das P P; Stewart A; Nederlof I; Barentsen K C; Portillo Q; Pannu N S; Nicolopoulos S; Gruene T; Abrahams J P

来源：Acta Crystallographica A-Foundation and Advances, 2016, 72(2): 236-242.

DOI：10.1107/S2053273315022500

• electron nanocrystallography
• Timepix quantum area detector
• carbamazepine
• nicotinic acid
• electron diffraction structure determination

Until recently, structure determination by transmission electron microscopy of beam-sensitive three-dimensional nanocrystals required electron diffraction tomography data collection at liquid-nitrogen temperature, in order to reduce radiation damage. Here it is shown that the novel Timepix detector combines a high dynamic range with a very high signal-to-noise ratio and single-electron sensitivity, enabling ab initio phasing of beam-sensitive organic compounds. Low-dose electron diffraction data (similar to 0.013 e(-) angstrom(-2) s(-1)) were collected at room temperature with the rotation method. It was ascertained that the data were of sufficient quality for structure solution using direct methods using software developed for X-ray crystallography (XDS, SHELX) and for electron crystallography (ADT3D/PETS, SIR2014).

• 出版日期2016-3