- Fundamental Physical Constants, NIST
- Fundamental Physical Constants and Conversion Factors, Freie University of Berlin
One of the most comprehensive periodic tables. Recommended
- NMR Periodic Table, Texas A&M
Contains information on NMR-active nuclei.
- Chemical Science and Technology Division, Los Alamos National Laboratory
Information on the history, preparation, sources, and uses of each element.
- ChemFinder, Cambridge Soft
Data on mp, bp, specific gravity, vapor density, solubility, etc of more than 60,000 compounds. Can search by name, formula, bp, mp, CAS RN, and structure. Structures can be converted to 3-D images in Chem 3D (Cambridge Soft).
- Spectrum Laboratories: Chemical Database
Physical properties and environmental impact data for a variety of compounds.
- Berkeley Smell's Database
List of compounds (with structures and properties) responsible for many odors.
- UIC Thermodynamics Research Laboratory, University of Illinois at Chicago
Links to sites containing thermodynamic constants, databases, and calculational tools.
- The NIST Chemistry WebBook, National Institute of Science and Technology
Thermodynamic data (gas phase and condensed phase), reaction thermodynamic data, gas phase ion energetics data, and infrared and mass spectra. Can search by formula, name, CAS registry number, molecular weight, ionization energy, and proton affinity.
- Integrated Spectral Database System, National Institute of Materials and Chemical Research, Japan
Mass spectral, NMR (proton and carbon), and infrared spectra (under construction) of more than 10,000 compounds.
- Vermont SIRI
180,000 MSDS records. Recommended.
- National Toxicology Program: Health and Safety Page
Contains toxicity data and physical constants. Not as comprehensive as some of the MSDS sites.