LibGuides: Chemistry: Key Tools...

Chemistry has many important research tools with long histories, first in print and subsequently online. The pages listed to the left highlight and explain resources that all chemists should know about.

Choosing the Best Tool

You'll save time and get better results if you start with the best tool for any particular task. Here's a table that might help you choose.

What do you want to do?	The best place to start:
Search for references (keyword, author names, title, abstract, journal, etc.	SciFinder, hands down. CAS is the most comprehensive literature index in any field and is hand-indexed, not machine-indexed. Web of Science covers the chemical journal literature fairly well, and eliminates patents and 'gray' literature that some chemists find distracting or irrelevant. However, WOS lacks chemistry-specific search features (systematic names, structures, RNs), and its search interface can be frustrating. Reaxys doesn't do this particularly well.
Search for substances by drawing a structure or substructure.	SciFinder and Reaxys are both very strong here. SciFinder's Registry database of indexed substances is by far the largest such resource in the world, but is heavily sourced from patents. Reaxys has a smaller universe of structures (but still millions), and some people prefer its structure editor to SciFinder's.
Search for reactions.	Reaxys is often preferred for its precision and drawing options. SciFinder has greater recall of organic reactions since 1986 because it indexes a far larger swath of literature. To be thorough you should search both. If you're looking for a preparation method for a compound, both tools let you draw a structure and designate it as a reaction product, and you can specify starting materials or fragments, catalysts, minimum yields, etc. SciFinder has a synthesis planner tool as well.
Search by citations to past literature.	Web of Science is by far the best tool. Its citation index goes back to 1900. It has relatively powerful tools to analyze results. SciFinder's citation indexing only goes back to the mid-1990s.
Search for chemical spectra.	SciFinder provides many NMR and IR graphical spectra from BioRad and Wiley libraries directly in Registry records for specific substances. It's also the best place to do a systematic literature search for published spectral data. Reaxys contains many spectral data fields in its substance records, which allow for peak searching, but does not contain graphical spectra. See the Spectroscopy guide for more information and lists of specialized spectral databases.
Search for crystallographic data.	The Cambridge Structural Database is the definitive repository for organic crystal data (see Crystallography guide page). Reaxys contains numerous searchable crystallographic data fields for many organic and inorganic substances. SciFinder is the best place to do a literature search for this information published in journals, starting with a substance search.
Search for physical and thermodynamic properties.	If you need basic property information about a well known compound, starting with a good online handbook, like the CRC Handbook, is the easiest path. Reaxys has the largest number of property data fields for substances, dating back more than a century. Complex numeric queries can be created to narrow down results, in addition to searching by substance. SciFinder has added a substantial amount of property data to its Registry records, but is not nearly as thorough as Reaxys. However, it's the best place to do a literature search for reported properties using keywords and Registry Numbers. See the Physical Properties guide for much more information and links to many specialized databases.