The Crystal Structure of Orthocetamol Solved by 3D Electron Diffraction. (11th July 2019) - Andrusenko, Iryna
Abstract: Orthocetamol is a regioisomer of the well‐known pain medication paracetamol and a promising analgesic and an anti‐arthritic medicament itself. However, orthocetamol cannot be grown as single crystals suitable for X‐ray diffraction, so its crystal structure has remained a mystery for more than a century. Here, we report the ab‐initio structure determination of orthocetamol obtained by 3D electron diffraction, combining a low‐dose acquisition method and a dedicated single‐electron detector for recording the diffracted intensities. The structure is monoclinic, with a pseudo‐tetragonal cell that favors multiple twinning on a scale of a few tens of nanometers. The successful application of 3D electron diffraction to orthocetamol introduces a new gold standard of total structure solution in all cases where X‐ray diffraction and electron‐microscope imaging methods fail. Abstract : Kleine Zwillinge, große Herausforderungen : Erstmals wurde 3D‐Elektronenbeugung genutzt, um die unbekannte Kristallstruktur von Orthocetamol, einer pharmazeutischen Verbindung, zu bestimmen. Die Struktur konnte nicht mit anderen Beugungstechniken bestimmt werden, da das System keine Einkristalle bildet, sondern vielfache Verzwillingung auf der Nanometerskala bevorzugt.