ChemExper is a company joining together the areas of chemistry, computer science and telecommunication. The ChemExper Chemical Directory is a free service that allows to find a chemical by its molecular formula, IUPAC name, common name, CAS...
ChemSpider is a chemistry search engine built with the intention of aggregating and indexing chemical structures and their associated information into a single searchable repository and making it available to everybody, at no charge. ChemSp...
Free chemical structure search engine. Millions of public domain structures. Very fast substructure searching. Results link to data about these structures.