Localization of hydrogen atoms in organic molecules using dynamical refinement of electron diffraction data

0470007 - FZÚ 2017 GB eng A - Abstrakt
Brázda, Petr - Klementová, Mariana - Palatinus, Lukáš
Localization of hydrogen atoms in organic molecules using dynamical refinement of electron diffraction data.
30th Meeting of the European Crystallographic Association. Book of abstracts. Acta Crystallographica Section A 72. Chester: International Union of Crystallography, 2016. S103-S103. ISSN 2053-2733. E-ISSN 2053-2733.
[European Crystallographic Meeting /30./. 28.08.2016-01.09.2016, Basel]
Grant CEP: GA ČR GA16-10035S
Institucionální podpora: RVO:68378271
Klíčová slova: electron diffraction tomography * dynamical refinement * hydrogen localization
Kód oboru RIV: BM - Fyzika pevných látek a magnetismus

Although, localization of hydrogen atoms in data from electron diffraction has been reported in special cases [1,2] reliable ab initio determination of hydrogen positions from single nano-crystals has not been achieved to the best of our knowledge. Our work focuses on pharmaceuticals and pharmaceutical co-crystals. The stability of these compounds under electron beam irradiation is low and data collection requires low-dose technique at low-temperature. Precession assisted electron diffraction tomography on single nano-crystals was used for data acquisition. Data were processed using programs PETS , Jana2006 and Dyngo. In favourable cases like in the case of paracetamol form I (S. G. P21/n), it was possible to localize a few of the hydrogen atoms in difference Fourier maps after kinematical refinement of the structure (R(obs) = 20 %). Dynamical approach provided an improved difference Fourier map, which revealed the complete set of hydrogen atoms (Figure 1).

Trvalý link: http://hdl.handle.net/11104/0267753