ChemSpider Owned by the Royal Society of Chemistry. Does not link directly to MSDS's, but but if you search for a chemical, it will return information including properties, sources, and links to journal articles, web articles, and MSDS's
ChemTube3D--Interactive This site contains interactive 3D animations for some of the most important organic reactions covered during an undergraduate chemistry degree with supporting information on reactivity and spectroscopy.
NIST Chemistry WebBook This site provides thermo chemical, thermo physical, and ion energetics data compiled by NIST under the Standard Reference Data Program.
Organic Compounds Database This 2483 compound database has been compiled by Harold M. Bell at Virginia Tech. Fill in the form with as much information as you can. Click on the submit button to execute your search. You will receive at most 20 hits
Chemistry Central Chemistry Central publishes peer-reviewed open access research in chemistry. Chemistry Central is part of the BioMed Central group.
NIST Chemistry Web Book This site provides thermochemical, thermophysical, and ion energetics data compiled by NIST under the Standard Reference Data Program.The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.