A Comparison of Structure Determination of Small Organic Molecules by 3D Electron Diffraction at Cryogenic and Room Temperature

3D electron diffraction (3D ED), also known as micro-crystal (MicroED), is a rapid, accurate, and robust method for structure determination of submicron-sized crystals. ED has mainly been applied in material science until 2013, when MicroED was developed studying macromolecular considered cryo-electron microscopy method, data collection usually carried out cryogenic conditions. As result, some researchers may consider that ED/MicroED on crystals small organic molecules can only be performed In this work, we determined the sucrose azobenzene tetracarboxylic acid (H4ABTC). The H4ABTC first crystal ever reported molecule. We compared quality accuracy among datasets collected under conditions room temperature. With improvement by merging, it possible to reveal hydrogen atom positions molecule structures both temperature experimental results showed that, if sample stable vacuum environment transmission microscope (TEM), at least good according various indicators (resolution, I/σ(I), CC1/2 (%), R1, Rint, ADRA).