The resources on this page will assist you in finding physical property information for a wide variety of compounds. The handbooks are listed in alphabetical order
The Aldrich/Sigma/Fluka Combined Catalog(http://hdl.library.upenn.edu/1017/8832) # is available online. You can search for a compound by name, CAS number, molecular weight, molecular formula, or density. In addition, if you download the structure plug-in, you can do a structure search through the catalog for the compound of your choice.
ChemExper Chemical Directory(http://hdl.library.upenn.edu/1017/14464) from the University de Lausanne in Switzerland, is a database of chemical compounds. Search by molecular formula, name, CAS number, catalog number, substructure, or physical properties. Chemists from all over the world are invited to submit data to the directory. It contains more than 70,000 compounds.
ChemSpider(http://hdl.library.upenn.edu/1017/93718) from the Royal Society of Chemistry, indexes over 25 million substances derived from some 400 sources. It is searchable by the usual chemical text fields, as well as by structure.
The CRC Handbook of Chemistry and Physics(http://hdl.library.upenn.edu/1017/6933) is located in all the science libraries on campus in print, as well as being accessible online. The chemistry library has several copies of the handbook in the reading room, and the most recent copy is kept behind the circulation desk.
The Combined Chemical Dictionary(http://hdl.library.upenn.edu/1017/97831) You name it, there is a dictionary about it! The Combined Chemical Dictionary contains such gems as The Dictionary of Organic Chemistry, The Dictionary of Inorganic Chemistry, The Dictionary of Natural Products, The Dictionary of Analytical Reagents, and many others. These are a good source of information if you want to find physical constants, structures, and properties of a particular compound encompassed by one of these areas. Most are available as multi-volume sets in the Chemistry Library Reading Room, although the online version is more up-to-date.
The Kirk-Othmer Encyclopedia of Chemical Technology(http://hdl.library.upenn.edu/1017/11413) is an excellent starting point for finding information on a kind of compound or type of process. It is arranged like any other encyclopedia, alphabetically with an alphabetical index at the end. It gives comprehensive background information, and it should be the first stop when researching an unfamiliar compound or process. Advanced high school students, too, can benefit from its clear explanations, although many of the reaction details can go a bit over their heads. This resource is located in the Chemistry Library reading room.
The Knovel Engineering and Scientific Online Reference Books(http://hdl.library.upenn.edu/1017/6967) is a compilation of over 1800 online reference books an monographs in all areas of science and engineering. The data search option allows you to search a goodly number of physical properties resources to find specific properties of molecules, as well as profile substances by property values (find me all substances that melt between -10 and 10C and boil around 100C at standard pressure.)
The Merck Index(http://hdl.library.upenn.edu/1017/56194) is a dictionary of drugs, organics, biologicals, and agricultural agents that contains more than 10,000 substances. It is substance, property, keyword and structure searchable, and entries include physical and chemical properties of the compounds, as well as of their derivatives.
NIST Chemistry Web Book(http://webbook.nist.gov/) is maintained by the National Institute of Standards and Technology and is an example of your tax dollars at work. It contains UV-VIS, IR, and NMR spectra for a fair number of organic compounds, as well as thermodynamic and physical data. You can search by formula, name, CAS number, structure, and molecular weight, among other things. Bear in mind that not every compound has spectra attached to it, however.
PubChemhttp://hdl.library.upenn.edu/1017/13802) from the National Library of Medicine is another example of your tax dollars at work. It focuses on the properties and biological activity of small organic molecules, many of which have been screened for anticancer activity and other therapeutic use. PubChem Compound is a curated database of unique molecules, derived from the PubChem Substance submission database, to which researchers can submit structures and properties that they determine in the course of their research. PubChem Bioassay is a database of assays and tests of groups of substances. All three interlink with each other, as well as with other databases available from the National Library of Medicine, including PubMed and the NCBI bioinformatics databases.
Reaxys(http://hdl.library.upenn.edu/1017/76928) brings together three separate handbooks, the Beilstein Handbook of Organic Chemistry, the Gmelin Handbook of Inorganic Chemistry, and the Elsevier Patent Chemical Database, resulting in millions of substances with hundreds of physical properties. It can be searched through various text fields, although the easiest way to find information on organic substances is through a structure search.