Chemistry

Browsable by chemical name, includes a list of most popular MSDS.

Database of NMR profiles for organic structures.

Institute of Chemical Sciences and Engineering, NMR prediction tool.

Maintained by the NCBI, PubChem is a database of chemical molecules and their activities against biological assays.

UK Repository for small-molecule organic and metal-organic crystal structures

Free chemical structure search engine containing public domain structures.

ChemSpider is a free chemical structure database providing fast access to over 34 million structures, properties and associated information.

From the Institute for Genomics and Bioinformatics at UC Irvine. Include structure information chemoinformatics tools.

Free database of compounds for Vvrtual screening

Chemical Profiles

Database of compounds with a focus on biochemistry and biomedical applications.

Enzyme database

Hazardous Materials

Compound database that includes gas phase IR, Mass Spectra and a few UV-visible spectra