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ChemSpider entry for caffeine

ChemSpider is a chemical structure database by the Royal Society of Chemistry (RSC) that provides access to over 50 million molecules, properties, and associated information from over 500 data sources including US Food and Drug Administration (FDA), Kyoto Encyclopedia of Genes and Genomes (KEGG), Molecular Diversity Preservation International (MDPI), US National Institutes of Health (NIH), US National Institute of Standards and Technology (NIST), Structural Genomics Consortium, Thomson Pharma, and Web of Science. By integrating and linking compounds from these data sources, ChemSpider provides a comprehensive view of freely available chemical data in a single online search.

A number of available search modules are provided, including the use of mobile devices via free apps for iOS and Android, allowing for querying systematic names, trade names, synonyms, and registry numbers. The advanced search allows interactive searching by chemical structure, chemical substructure, using also molecular formulas and molecular weight ranges, Chemical Abstracts Service (CAS) registry numbers, and suppliers.

interactive 3D model of caffeine 1
interactive 3D model of caffeine 2

This can be done because each chemical is given a unique identifier, which forms part of a corresponding URL, e.g., caffeine (1,3,7-Trimethyl-3,7-dihydro-1H-purine-2,6-dione) is 2424 and thus has the ChemSpider URL

Besides offering a static, two-dimensional structural formula of the molecule, ChemSpider also offers an interactive three-dimensional model which can be viewed via Jmol (using a Java applet) or JSmol (a JavaScript framework for Jmol to display on devices that do not have Java installed or for which Java is not available, e.g., smart phones and some tablet computers).