For immediate assistance with SciFinder (Monday-Friday, 9am-5pm), call the Chemistry Library at 512-495-4600. Outside of business hours, or to get more information including answers to questions about access, troubleshooting, searching, and links to full text,
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- What is SciFinder?
- SciFinder is a system that provides integrated, user-friendly, point-and-click access to several Chemical Abstracts Service databases plus Medline:
- Chemical Abstracts (CAPLUS, bibliographic data, 1907-present)
- Registry (chemical structures, biosequences, and names, with associated property and spectral data)
- CASREACT (single and multistep organic reactions, 1840-present),
- CHEMLIST (regulatory information on chemicals)
- CHEMCATS (commercial availability of chemicals from major suppliers)
- MEDLINE (biomedical literature, 1949-present)
You can search more than 30 million documents by topic, author, CAS Registry Numbers, patent number, and CAS abstract number. More than 40 million chemical substances may be searched by chemical name, structure, Registry Numbers, and molecular formula. You can also execute substructure searches for substances, biosequences, and organic reactions.
- How often is the database updated?
- The Chemical Abstracts databases (CAPLUS and Registry) are updated daily with thousands of new records. It takes anywhere from a few days to a few weeks for a newly published article or patent to appear in CA. In journals that publish new articles online before they appear in print, CA usually indexes the online version first, then updates the record when the print appears. CASREACT is updated weekly.
- How does the Research Topic query really work?
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The Explore by Research Topic option presents a single text box that looks like Google's, but SciFinder's search algorithms work VERY differently from those of standard web search-engines. SciFinder uses a proprietary, highly complex (and somewhat mysterious) natural language query algorithm that breaks what you type into a set of discrete concepts, searches them against the database indexes, and then presents you with a selection of result options. Here is a very brief list of important searching points unique to SciFinder Scholar -- these apply to no other database tools or web search engines.
- Compose a natural-language query phrase with at least two distinct concepts, linked with prepositions. Examples:
single walled carbon nanotubes in thin film transistors
synthesis of fluorescein derivatives
determination of arsenic in wood pulp
- SciFinder uses prepositions to break your query down into component concepts, but prepositions are not analyzed for linguistic meaning. Example: 'determination of arsenic' = 'determination in arsenic'.
- Avoid long, complex queries. Try to keep them straightforward and brief, with no more than 3 or 4 distinct concepts. If your topic is complex, do a simpler search to start with, then narrow down the results using the Analyze/Refine option.
- Don't use Boolean operators (AND, OR). Inserting NOT will usually work to eliminate concepts you don't want.
- Slight differences in the way your phrase a query can retrieve markedly different results, so you may want to try your search several different ways if your first results aren't satisfactory.
- If you want to search an exact phrase, type the phrase without quotation marks (which are ignored), and select the first option in the results list: "X references were found containing 'A B C' as entered." You will only see this option if there was an exact match in the database. Note that none of the processes described below will have been performed on this exact phrase.
- SciFinder auto-truncates your words in most cases, so don't use truncation symbols like * or # -- these will be ignored.
- SciFinder is case-insensitive. AIDS = aids.
- Using general keywords does not automatically retrieve more specific concepts. Example: 'metals' will not also retrieve 'gold' or 'platinum', etc. You can treat them as synonyms though.
- You can include up to three synonyms in parentheses, separated by commas, following the word in question. Example: 'lead poisoning in humans (men, women)'. You don't need to do this for simple plurals -- SciFinder truncates most plurals automatically and includes both in your results. SciFinder also uses an internal thesaurus of synonyms, so you'll occasionally see words you didn't search included in your results.
- SciFinder recognizes and translates some abbreviations and British vs. American spellings. Examples: 'NMR' = 'nuclear magnetic resonance'; 'color' = 'colour' etc. Abbreviations that are ambiguous or non-standard will not be translated in this way.
- Chemical names included in topic queries are automatically searched in the synonym index of the Registry file, and if an exact match is found that compound's Registry number is added to your query.
- You can use a Registry number in the Topic query box, but for best results you should start with the Substance Identifier option instead. For example, you can type 'synthesis of 5467-78-6' in the query box, but it would be more precise to type the number in the Substance Identifier box and then limit reference retrieval to articles on Preparation.
The Research Topic option is meant to be user-friendly and inclusive, and to retrieve good results for almost all types of queries. However, it is not meant to be a highly precise keyword search mechanism for expert searchers. For more information, consult the Help pages.
- How are records in a results set sorted?
- The default sort for references is by "accession number," which is essentially the same as reverse-date: newest documents on top. You can resort a results set by author, document title, or reverse publication year. Substance records are default sorted by Registry Number, which means that the most recently reported substances - which usually have few or no references - are on top. It is more useful to re-sort by Number of References, which will bring the best-known substances to the top.
- What does the Analyze feature do?
- Analyze is a tool that allows you to evaluate and review an answer set without having to browse all the entries one by one. You can create histograms of your set based on author name, organization/company, language, docuement type, journal title, date, CAS Registry Number, and so on. This can help you quickly identify individuals or organizations doing work on your topic, chemical substances most frequently mentioned, key publications, trends over time etc. You can click on a histogram bar and view just those records.
Another way to analyze a reference result set is to use the Categorize feature. Choose a broad subject category from the list on the left, then select one or more CA index terms from the right side and view just those records. This technique utilizes the power of CAS' controlled indexing vocabulary and works very nicely for sifting large answer sets.
You can analyze a substance answer set by real-atom attachments, variable group and R-group, precision, ring skeletons, and stereochemical precision. This helps narrow down a large substance answer set to zero in on structures of particular interest.
Finally, if you are searching by drawing a chemical reaction, you can analyze a reaction result set by catalyst, solvent, number of steps, product yield, as well as bibliographic data such as author, journal, year, document type, etc.
See the How To Guides for more details.
- How can I limit a substance answer set that's too large?
- The Refine and Analyze tools allow you to narrow your substance results by a number of criteria, including additional structure component, metal- or isotope-content, property data or commercial supplier information, etc. For instructions and examples see CAS' How To Guides page.
- How do I search for chemical names?
- Carefully. Use the "Substance Identifier" option. Chemical nomenclature in general is very complex, and follows different sets of rules. CAS uses its own nomenclature rules to name chemical substances, and these have changed substantially over the years. The Registry database indexes the current official CA Index Name for all compounds, along with any former CA Index Names and various synonyms and trade names that have been used in the literature. (However, Registry is not a comprehensive source of chemical names and trade names.) It's relatively easy to search by well-known common names (ex. acetic acid, cyclohexane, acetaminophen), familiar trade names (ex. Taxol), and abbreviations (ex. MTBE). Searching systematic names is less reliable because of the many possible variations in a name string.
The system looks first for an exact match to the name as you type it. If
it finds an exact match, it displays only that compound, and no others. For
example, if you search for "Gallopamil" it will retrieve the compound that has
that exact name, but it will NOT retrieve "Gallopamil hydrochloride" (or any salts or multicomponent compounds). If it doesn't find an exact match, it next looks for the string you entered as a segment in a name. It will display all such partial matches. Browse these results, or analyze/refine your results to narrow them. It is not currently possible to browse an alphabetical index of names in SciFinder.
As with all chemical database tools, the chemical name is not the best way to
search for a compound because of the complexity and inconsistency of chemical
nomenclature and the diversity of synonyms and trade names used in the
literature. Never rely on a name search when doing a comprehensive search for a
compound. The rule of thumb is, when in doubt, draw it!
- How do I search by molecular formula?
- Under Explore Substances/Molecular Formula tab, enter the formula in any element order but add up the atoms (ex. Benzoic acid is c7h6o2 not c6h5cooh). SciFinder will parse the formula and ask you for clarification if it's ambiguous. Some formulas are case sensitive if ambiguous (ex. si could be Si or SI) or spaces may be required. Separate the components of a multicomponent substance with a dot (ex. Sodium benzoate would be C7H6O2 . Na -- note that the "extra" hydrogen in the COOH group IS included in this component's formula).
Molecular formula searches often retrieve large numbers of hits. You can sort them by Registry Number or number of literature references (the latter is best because you're usually looking for the record with the most literature associated with it). You can also use the Analyze/Refine tool and draw part of the structure to narrow them down, or try another kind of search.
- How do I transfer a Registry structure into the drawing module to modify it?
- View the Registry compound record with the structure in question. Click on the structure diagram and choose "Explore by chemical substance" (or reaction). The structure will be imported into the drawing module and can be modified for further searching. This is a useful shortcut to drawing a complex structure.
- How do I search for the preparation of a compound?
- You can pre-limit a substance search to preparation by selecting that option from the Studies menu. Or you can do a search by Registry Number, structure, molecular formula, or chemical name, and mark the compound(s) you wish to explore further. Click "Get References". On the limiting menu, select the Preparation role. (Registry numbers in document records where a preparation method is described are assigned this role. The Preparation role has been retroactively added to Registry numbers back to 1907.)
To search for specific synthetic pathways, see the Synthetic Pathways Overview.
- How do I search for polymers?
- Since many polymers have unknown or indefinite structures, CAS registers most polymers as multicomponent substances composed of one or more monomers. You can search by name, monomer structure or formula and limit retrieval to polymers in the Class(es) menu. Search for general classes of polymers as a research topic. Structure searching for copolymers in SciFinder involves executing a search for one monomer as an exact structure, then refining the results by adding another monomer. It's best to start with the less common monomer. Polymers with undefined structures obviously can't be searched by structure, but must be found with name and class terms instead. For instructions and examples see the Polymer Searching Overview on the SciFinder Solutions web site. More in-depth documentation can be found here.
- How can I remove multicomponent substances from my answer set?
- After drawing the structure, select "Single component" from the Characteristics menu. This will in many cases substantially reduce your number of hits. This option has to be selected before the structure search is run; it's not a Refine option.
- Can I search for chemical substances by property value(s)?
- Only indirectly. Many substance records in the Registry file contain calculated or experimental property data. These data are not directly searchable in SciFinder -- for example, you can't do a search for all compounds with a particular melting point. But you can refine a substance set by experimental property values. See the help pages for more information. Experimental property data in Registry come mostly from the literature; predicted properties and spectra are generated by algorithms from ACD Labs.
Direct property searching is possible in the Reaxys database, which has powerful property searching options. The Combined Chemical Dictionary and Properties of Organic Compounds databases also allow searching by property values.
- How do I locate commercial chemical suppliers?
- Search for a compound by name, structure, formula, Registry number, etc. View the record for that compound. Click on the "Get Commercial Sources" button
to view a list of commercial suppliers and addresses.
- Can I find current regulatory information on substances?
- Yes. Do a search for the substance and locate its Registry record. Then click on the "Get Regulatory Info" link to pull up the compound's CHEMLIST record.
- Why do some substances show zero references?
- Although most Registry compound records come from CAS' indexing of the literature, some compounds are registered via other sources and are not necessarily represented by any indexed literature. Third-party chemical libraries, catalogs, and databases from various external agencies, as well as hypothetical ring parents are also included. For more information see CAS's STN Guide article on this topic.
- How do I search for chemical reactions?
- Select "Explore Reactions" from the task menu. Draw a reaction scheme including one or more reactants/reagents, a reaction arrow, and a product (sub)structure. You can focus your substructure search more narrowly and avoid error messages or too many hits by using the locking tools, mapping atoms, and defining reaction sites (bonds broken or formed) in the drawing module. You can also apply pre-limits such as solvent, number of steps, classification, year, etc. Click "Get Reactions" to run the search in the CASREACT database. For more information see the How to guides.
- Where does SciFinder's reaction information come from?
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The CASREACT file contains records with reaction information derived from journals and patents covered in the Organic sections (which include organometallics) of Chemical Abstracts since 1985. This content is augmented by a selection of third-party reaction files stretching back to 1840: VINITI/ZIC; INPI; Wiley reference works, etc. CASREACT is not as broad as Beilstein in its reaction coverage before 1985. For best coverage you should search both sources.
- Are the cited references in the CA record searchable?
- Yes. Cited references (representing the works appearing in the article's bibliography) are included in CA bibliographic records back to 1996. Most are hyperlinked to the corresponding record in CA -- just click on the citation to go to that record.
To find later documents that cite a specific work or group of works (such as by author), pull up a group of records, select one or more (or just use the entire results set), and click "Get Citing" in the task bar. This will pull up a set of documents (post-1996) that cited the selected original(s).
Web of Science (Science Citation Index) allows more extensive analysis of citations, and calculates an h-index, which SciFinder can't do. It's also the only source to find pre-1996 citing papers. [More information on citation searching]
- How do I search for older literature?
- The 1907-1966 segment of CAPLUS is fully searchable. All indexing data for chemical substances from the 1st through 7th Collective Indexes have been added and algorithmically matched with Registry Numbers. Exception: If you start from a chemical substance record, click Get References, and then select from the Roles menu (Adverse effect, Analytical study, etc.), you will retrieve results only from the 1967+ file segment. To confuse matters further, the Preparation role has now been added back to 1907. SciFinder and the help pages do not make these distinctions clear.
CAS is selectively adding bibliographic records for pre-1907 literature from other sources. Beilstein and Gmelin are excellent alternatives to search for older literature. See the Historical Literature pathfinder for more information on pre-1907 searching.
- Can I search CA abstract numbers in SciFinder?
- Abstract records from 1967 to present can be searched by abstract number (e.g. 101:59753) in the Document Identifier tab. 1907-1966 abstract numbers are not searchable or displayable in SciFinder. These are the numbers that look like: 53:2185a, indicating that the original abstract appeared in volume 53 of printed Chemical Abstracts, in column number 2185, position "a" (top of the column). These positional numbers did not necessarily correspond to a specific abstract and thus one-to-one matches aren't possible.
The "CAN" number displayed in the CAPLUS file for records prior to 1967 is a computer-generated accession number which does NOT correspond to the printed CA. It looks like this: 1966:10072 or 64:10072. If you have only an old CA abstract number, you must use the print CA to find the abstract. If you need to find a genuine CA number for an older reference, you can look it up in the print, or ask the librarian for assistance.
- Does Chemical Abstracts index translation journals?
- Originally, up to about 1995, CAS indexed only the original journals (mostly Russian), and ignored their English translation counterparts. Starting in 1995 CAS began to switch to selected translations when they were apparently simultaneous and complete. [More information on translation journals]
- What patents does CAS cover?
- CAS indexes chemical patents from around the world. Its coverage is both thorough and timely. To see information about this coverage and interpreting patent records retrieved in SciFinder, see CAS' Patent Coverage web pages. While CAS does cover chemical patents very well, the SciFinder interface is not designed or recommended for comprehensive patentability (prior art) searching, which should be done by experienced patent searchers using specialized databases. And remember that the academic usage terms prohibit using SciFinder for any profit-making purpose, regardless of one's academic status.
- How can I remove patents from my results?
- Click the Refine tab from a results screen, then choose Document Type, and select from the menu only those types of documents you wish to see.
- How can I remove the Medline records from my results?
- Medline records are sorted separately in results sets, and come after the hits from CAPLUS. After you get a list of references, click the Refine tab, then select the Database button and select CAPLUS. (Many Medline records might be duplicates of CAPLUS records in the same set. SciFinder allows you to remove duplicates from your results set, although this is not foolproof.)
- Can I set up an Alert to send me new records?
- Yes, you can set up a Keep Me Posted alert within your account. See the How To Guides for instructions.
- Can I save answer sets from session to session?
- Yes. You can save a results set (references, substances, or reactions) on the CAS server, or export them to a local disk, then combine a future results set with that saved set if you wish. By employing various options of Combine, Intersect, or Remove, you can manipulate and customize the information contained in these combined answer sets.
- Is there still a reason to search for organic compounds and reactions in Beilstein?
- Yes. SciFinder and Beilstein are complementary resources, and although there is some overlap the two are quite different in the ways they scan and index the literature, the ways they register compounds and index reactions, and in the dates they cover. Beilstein offers physicochemical data, preparation/reaction references, and coverage of older (pre-1960) journal literature. SciFinder offers very thorough coverage of the literature and patents from 1967 forward and comprehensive registration of all types of chemical compounds and structures. CAS also scans far more journals than Beilstein does now. As a rule of thumb, start with SciFinder for substances reported after 1967 and reactions after 1985; start with Beilstein for substances and reactions reported before 1960. Use both for the middle period of 1960-1985. Organic and medicinal chemists should routinely consult both databases for the most complete coverage of organic compounds and reactions. See a comparison chart for side-by-side comparison.
- Should I use SciFinder or Web of Science?
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SciFinder and Web of Science are complementary but not directly comparable. They differ significantly in scope, coverage, dates of coverage, and indexing methodology. CAS databases are superior for coverage of the chemical literature comprehensively in all its forms, and for indexing of chemical substances, structures, synonyms, properties, and reactions. Web of Science is an interface to ISI's Science Citation Index, which was created primarily as a tool to search for cited references in selected source journals across all the sciences. While WOS covers a large number of key chemistry journals, it offers only keyword and author searching and abstracts, without any enhanced chemical indexing or structures. If you really need to search the chemical literature using features a chemist needs, use SciFinder. If you need to search and analyze cited references, use Web of Science. See a comparison chart for side-by-side comparison of these two tools.
For immediate assistance with SciFinder (Monday-Friday, 9am-5pm), call the Chemistry Library at 512-495-4600. Outside of business hours, or to get more information including answers to questions about access, troubleshooting, searching, and links to full text, contact us via email.
