Searching the Literature
Bibliographic databases (i.e., indexes) are vital for searching the primary literature, but they are not optimally designed for locating property data contained within original documents. The SciFinder
interface to the Chemical Abstracts database
can be searched for documents since the late 19th century that may contain desired physical property information. If the data in question were the main topic of the article, values may be shown in the abstract. But if the document gave the data in passing rather than as the main focus, the abstract and indexing may give no indication of it. The quality and thoroughness of CA's human indexing varied over the years, and was generally less consistent in the decades before 1960. Trying a search several different ways can make a difference. You can search either by References or by Substances:
Start with the Research Topic query using a property name connected to the substance's Registry Number or common name.
dissociation constant OF 7778-77-0
heat formation AND 10045-86-0
enthalpy vaporization OF alumina
- The OF operator causes SciFinder to look for records that contain both the property name and the RN anywhere in the record. You can choose the references with the concepts "closely associated with one another" to increase precision further. The AND operator just looks for the concepts anywhere in the record but doesn't offer the proximity option.
- If the property index term contains a connector, such as OF in "Heat OF formation," omit the connector from your query.
- SciFinder automatically includes certain synonyms and plurals in your search. For example, heat = enthalpy and both terms will be retrieved by searching one of them.
- Use the RN as a search term in place of a chemical name. Your search will be more precise by avoiding name-fragment hits that are not directly related to the compound you're seeking. However, see the next tip.
- When CAS converted older years of CA to digital format, the Registry Number for a substance was algorithmically assigned to the article record ONLY if the original Subject Index for that period included a reference to the article under the substance's CA Index Name. In some cases, CA abstracters only made this assignment when the substance was the main focus of the document, ignoring other compounds that may have been mentioned. (The conversion project made no attempt to re-analyze or re-index the original literature.) Searching by common name instead of RN occasionally yields some articles where the name appears in the title or abstract but was not specifically indexed for some reason.
Start from the Explore Substances search:
- Search for a substance by Registry Number, molecular formula, name, or structure.
- Click "Get References" and retrieve references from all years.
Selecting "Properties" from the"roles" pop-up menu will retrieve only post-1967 references. (The Properties role has not been retrospectively assigned to RNs before that date.) Since much fundamental property data was reported before that time, you should skip this menu and just get all references.
- Use the Refine tab to limit the results set using a property name.
An Alternative to Traditional Indexes: Thermophysical Properties Research Literature Retrieval Guide