You can also download specific records from PubChem.
Click on the Best Match for Sarin.
Find the Download button above the Contents menu. Click it to see options for downloading data used to display this page, 2D structure, or 3D conformer. It is noteworthy that the 3-D conformer downloaded in this way is not an experimental structure. It’s computationally generated to mimic bioactive conformation (which can be found in a protein-ligand co-complex). Please see the PubChem3D release note.
Additionally, some individual sections of a Compound summary can be downloaded.
Use the Contents menu to jump to the Literature section of this summary. Scroll down to the NLM Curated PubMed Citations. The Download button is located at the top of the section.