Accurate structure models and absolute configuration determination using dynamical effects in continuous-rotation 3D electron diffraction data

Abstract

Continuous-rotation 3D electron diffraction methods are increasingly popular for the structure analysis of very small organic molecular crystals and crystalline inorganic materials. Dynamical diffraction effects cause non-linear deviations from kinematical intensities that present issues in structure analysis. Here, a method for structure analysis of continuous-rotation 3D electron diffraction data is presented that takes multiple scattering effects into account. Dynamical and kinematical refinements of 12 compounds—ranging from small organic compounds to metal–organic frameworks to inorganic materials—are compared, for which the new approach yields significantly improved models in terms of accuracy and reliability with up to fourfold reduction of the noise level in difference Fourier maps. The intrinsic sensitivity of dynamical diffraction to the absolute structure is also used to assign the handedness of 58 crystals of 9 different chiral compounds, showing that 3D electron diffraction is a reliable tool for the routine determination of absolute structures.

Unveiling the topology of partially disordered micro-crystalline nitro-perylenediimide with X-aggregate stacking: an integrated approach

“…63 Therefore, it was necessary to model the multiple scattering using dynamical refinement. 64,65 After the refinement, it was possible to localize the positive maxima due to the atoms of the aliphatic tails (Fig. 3).…”

The Elusive Structure of Levocetirizine Dihydrochloride Determined by Electron Diffraction

“…[37] The atom coordinates were fixed and the structure was refined Unambiguously, the residuals for the R-form were superior to the residuals of the S-form, thus the Rform was assigned (Supporting Information Table S2). [12,41] It should be mentioned that dynamical refinement of a single ED dataset from a commercial Levocetirizine dihydrochloride tablet may not be representative of the whole production lot. Other analytical techniques to determine the chirality of the sample were not employed.…”

Applications of Transmission Electron Microscopy in Phase Engineering of Nanomaterials

“…Though the 3D ED method does not require zone-axis orientation and can be semiautomated, , it still requires manual selection of the targeted crystals and checking the sample drift during data collection. A recent work by Klar et al achieved the high-throughput determination of absolute structures from compounds using continuous-rotation 3D ED data with multiple scattering effects taken into account, opening the door for further automation for determining various structures from enantiopure compounds without the need of single crystal growth …”