EMolecules

eMolecules is a search engine for chemical molecules. The system was first launched in November 2005.

Database

 * The database contains more than 7.0M unique molecules from commercial suppliers, like Acros, ASINEX, ChemBridge, ChemDiv, Comgenex, Enamine, Fluka, Key Organics, Life Chemicals, Maybridge, Otava, Sigma-Aldrich, Specs, and many more.
 * The database contains also all entries provided by NIST, PubChem, and DrugBank. Duplicated (non-unique) index numbers are resolved automatically.

Searching
Two public available search modules are provided
 * The standard search allows querying for names, substructures, and suppliers.
 * The expert search allows interactive searching using also a molecular weight range, CAS numbers, suppliers, etc. The search can be used to widen or restrict already found results.