PubChem is an open chemistry database at the National Institutes of Health (NIH) containing information on chemical structures, identifiers, chemical and physical properties, biological activities, patents, health, safety, toxicity data, and many others.
Common Chemistry from Chemical Abstracts Service (CAS) contains CAS Registry Numbers for approximately 7,900 chemicals of widespread general public interest. Common Chemistry is helpful to non-chemists who know either a name or CAS Registry Number of a common chemical and want to pair both pieces of information.
ChemSpider is a free chemical structure database providing fast access to over 63 million structures, properties, and associated information. By integrating and linking compounds from ~280 data sources, ChemSpider enables researchers to discover the most comprehensive view of freely available chemical data from a single online search. It is owned by the Royal Society of Chemistry.
Spectral Database for Organic Compounds is an integrated spectral database system for organic compounds,which includes 6 different types of spectra under a directory of the compounds. The six spectra are as follows, an electron impact Mass spectrum (EI-MS), a Fourier transform infrared spectrum (FT-IR), a 1H nuclear magnetic resonance (NMR) spectrum, a 13C NMR spectrum, a laser Raman spectrum, and an electron spin resonance (ESR) spectrum. Approximately 34,000 compounds are in the database. Records include graphical structures and spectra, with peak assignments in many cases. Compounds may be searched by name, molecular formula, molecular weight, CAS Regostry Number, number of atoms/elements, and spectral data.