Chemistry

National Institute of Standards & Technology (US)

National Physical Laboratory (UK)

International Union of Pure and Applied Chemistry

For more than a century, the CRC Handbook of Chemistry and Physics has been a trusted source of reliable scientific data. It contains thousands of physical and chemical data tables which are reviewed and updated on an ongoing basis.

ChemIDplus, from the National Library of Medicine, is a free search engine containing approximately 350,000 chemical compounds.

A free chemistry search engine that provides access to data on more than 29 million structures.

PubChem provides information on the biological activities of small molecules.

SciFinder contains calculated and experimental property data (with references) for approximately 81 million organic and inorganic compounds.

An essential and well-known source of authoritative chemical and physical property data for thousands of compounds.

Originally published in 1926-1930, this well-known resource contains a wealth of critical data on inorganic and organic compounds, and pure substances.

KCT contains tables of physical properties for more than 13,000 commonly used chemical compounds.

Lange's includes tables of properties of approximately 4,400 organic and 1,400 inorganic compounds.

A free database containing physical and chemical property data for approximately 70,000 compounds.

The Sigma-Aldrich Catalogue covers more than 40,000 chemical products and is particularly useful as a starting point because entries include molecular and structural formulas, basic physical data, MSDS data and cross-references to PubChem, Reaxys (Beilstein), and Merck.

A classic reference source that comprises more than 900 tables of common physical and chemical data.

Contains chemical and physical data; health, safety and environmental data; and supplier listings for several hundred common solvents. Compiled by the National Center for Manufacturing Sciences (NCMS).

Includes IR, MS, UV/Visible, vibrational and electronic spectra.

Public database of NMR spectra for approximately 42,000 compounds.

Contains IR, MS, NMR, Raman and ESR spectra for about 34,000 compounds.