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Beilstein Handbook

Gmelin Handbook

Organic Chemistry Guide

Inorganic Chemistry Guide

Finding Data 101


A new, redesigned Reaxys interface launched on October 17, 2016. Users are advised to view a free webinar to familiarize themselves with the new look. The old Reaxys interface will be retired in May 2017. The FAQ below are based on the old interface and will be updated in the coming months.

Consider attending other free Reaxys Webinars to expand your search skills. Live webinars are archived for later viewing.

Questions & Answers

What is Reaxys?
What are its sources?
What patents are covered?
What substances are covered?
How often is it updated?
Can I search by CAS RN?
Can I search chemical names?
Can I search molecular formulas?
Can I search by print Beilstein reference?
How do I find property data?
Can I search by property values?
Are properties critically evaluated?
Are there spectra?
What are PubChem records?
What is the Ask Reaxys box?
What does the Literature search do?
Does it link to full text?
Can I save results and set up alerts?
Can I export to EndNote?
Can I use from off campus?
What structure editors are supported?
Structure applet won't open?
What about SciFinder?
What about the printed handbooks?
What documentation is available?
What is Reaxys?
Reaxys provides information about millions of chemical structures, reactions, and properties. It is an important tool for researchers who are synthesizing and characterizing chemical compounds, or searching for data on the physical, chemical, spectral, or toxicological properties of chemical substances.

What are the sources of Reaxys content?
Reaxys merges content from various data sources:

Current Extraction from Selected Core Journals
Until 2010 about 175 journals were indexed for Beilstein and about 60 for Gmelin, though update frequency varied considerably. After 2010 journal coverage grew towards 400 core chemistry titles for both segments combined. (The increase was not retrospective, and a list of these 400 titles is not publicly available.) Coverage within a journal is highly selective. Data are only excerpted if they have a structure, experimental fact(s) and a credible citation.

Beilstein Handbook
The Beilstein Handbook up to 1959 (Supplement IV) was the core source of historical content for organic compounds and reactions. Beilstein was a definitive source of information on the structures, reactions, and properties of organic carbon compounds, drawn from the journal literature back to the 18th century. (Due to licensing issues, the "Beilstein" name isn't used anywhere on the Reaxys site.)

The Gmelin Handbook up to 1975 was the historical source of structures and properties of inorganic and metal-organic compounds, drawn from the journal and patent literature back to the early 19th century. After 1975, information was extracted from a small group of selected journals with varying degrees of thoroughness and timeliness. Gmelin's coverage of the literature was always uneven and not comprehensive. See our Gmelin page for more details.

Patent Chemistry Database
Organic substances and reactions are excerpted from selected English-language chemical patents (US, WO, EP, 1976- ).

What is the patent coverage in Reaxys?
The Beilstein Handbook included selected worldwide organic chemical patents from about 1920 to 1980. Gmelin also covered chemical patents. The Patent Chemistry Database covers selected English-language chemical patents (US, WO, EP) since 1976, based on a subset of IPC codes. Prefer SciFinder (Chemical Abstracts) for more complete chemical patent coverage.

What kinds of substances are in Reaxys?
Chemical compounds with defined structures and/or molecular formulas are covered. In general, polymers, biological molecules (peptides, proteins, nucleic acids, enzymes, etc.), engineered materials (ceramics, alloys, etc.), and multicomponent mixtures are not included in the core substance-based segment of Reaxys.

How often is the database updated?
The database is updated biweekly. However, this doesn't necessarily mean that new articles are indexed within two weeks of publication.

Can I search by CAS Registry Numbers?
Yes, but don't give up if it doesn't get a hit. Beilstein substance records created prior to 1994 ususally contain RNs as chemical identifiers. Some substance records added since 1994 do not. Not all Gmelin substance records contain CAS RNs. CAS RNs should not be confused with Reaxys registry numbers, which are accession numbers within this database alone.

A single substance record in Reaxys may contain several CAS RNs because the two systems use different registration rules. CAS assigns RNs to structures more narrowly than Reaxys.

Can I search by chemical names?
Yes, but this is the least reliable kind of search. Reaxys indexes various synonyms for compounds, but don't rely solely on name string searching. Some names are given only in German. CAS Registry Numbers and exact structures are better starting points. You can also generate a structure from a name, which you can then edit for further searching.

Can I search by molecular formula?
Yes. Use the Formula Builder tool to create a proper query. This is especially useful for inorganic and organometallic/coordination compound searching, and for building queries with variable element counts and element groups. A similar Alloy tool lets you create MF searches specifying element percentages.

Can I search by an old printed Beilstein or Gmelin reference?
No, you have to look up the actual compound. Some handbooks, such as the Aldrich Catalog, still list Beilstein volume/page references (e.g. "Beil. 13, III, 2311"), but Reaxys does not include these at all. Some inorganic substance data tables do provide the corresponding Gmelin Handbook reference alongside the source journal reference, but they are not searchable.

What's the easiest way to find a property data value for a known compound?
  1. Select the "Names and Formulas" tab.
  2. Enter the CAS Registry Number in the appropriate box. (If the RN is in the Reaxys index you'll see it in the pull-down list as you type.) Click OK, then click Search on the next form. (If you don't have the CAS RN, or if you get no hits, do a search by structure, molecular formula, or chemical name.)
  3. In the table entry for the matching compound, click "Show Details" or the appropriate link under "Available Data".
  4. Open the desired data category to view the data table.

Can I search by property values?
Yes, but it can get complicated. Under the Names and Formulas tab, click on the Properties button and select property fields and enter values, which will then appear in search syntax form in the query box. Due to the huge number of property values in the Reaxys database, this technique is most useful in conjunction with a substructure search, and if you enter a range of values for a property it's best to keep that range narrow to avoid large results sets. You can also use the "exists" operator to limit to substances that contain a particular field without having to enter values for that field. Remember also that a substance record might contain many values for a given property in a table, based on different conditions, and from different sources. To ensure that queried subfields are found in the same row of a data table, use the Proximity operator in the Advanced tab instead of the And operator. Example syntax: BP.BP='69-72' PROXIMITY BP.P='760'

Are property data in Reaxys critically evaluated?
Some data derived from the print Handbooks were originally assessed for consistency, but more recent data excerpted directly from the literature are not. And since there's no way to tell the difference, you have to assume it's not. (Data taken from patents should be viewed with particular skepticism.) All excerpted data are experimental, however - not derived or calculated.

Does Reaxys contain spectra?
Reaxys contains plentiful spectral data (peaks, solvents, etc.) on chemical compounds as reported in the primary literature, but no spectral graphs. You can use the form-based search to specify spectroscopic data with various parameters. More information

Why are PubChem records shown in Reaxys?
Reaxys automatically searches the NIH PubChem database in parallel when you do a substance structure/identification search. PubChem results are loaded under a separate tab and you can toggle back and forth between the two lists. This can be a bit confusing when you get PubChem hits but no Reaxys hits. If you enter additional Property search parameters, these are ignored in the PubChem search since the latter's data structure is very different. Reaxys and PubChem are separate databases that are otherwise unrelated. Reaxys is literature-based; PubChem is crowd-sourced.

What is the Ask Reaxys search box?
This feature is analogous to SciFinder's topic search box. It parses your terms and attempts to find the most relevant hits. It works fine for some very straightforward searches, such as "preparation of 12078-17-0" where the algorithm can make a relational match between a concept and an unambiguous substance identifier. But it is still being developed and doesn't always get it right. When you use it for non-chemical concept searches it'll drop you into the Literature search, or into external substance files like PubChem. The search forms are still a more reliable entry point into the core database of substances and reactions.

What does the Literature search do?
This tab allows you to search across a bibliographic database that includes the source articles and patents for Reaxys chemical information (structures, reactions, properties), as well as about 16,000 other periodical sources that have been added from various Elsevier bibliographic files more recently. These additional sources are not necessarily chemical in nature, and are NOT analyzed for chemical data and content in the way that the 400 "core" journals are. Reaxys is not a comprehensive literature index: if you need to do a general topical/keyword literature search, it's better to use SciFinder or another appropriate subject index.

The "basic index" field searches for words found in titles, abstracts, and indexing terms. You can also use the form to search for author names, patent assignees, journal titles, and numeric fields like year, volume and page numbers.

Does Reaxys link to full text of journals?
Click the "Find It @ UT" button in the citation records to initiate a local search for electronic full text. However:
  • Many legacy citations from Beilstein and Gmelin are quite old and/or obscure, and full text may not be available.
  • Bibliographic metadata may be incomplete, preventing our local database from making a match.
  • If you don't find electronic full text, be sure to check our Catalog for our extensive archival print holdings.

Can I save searches and set up alerts?
Yes. You need to create a personal registration in Reaxys first. Then you can change the application settings, save queries and search history, and set up alerts.

Can I export references into EndNote?
Yes. When you open the Output tool, select "Literature Management Systems" for output format, and then import into EndNote or another bibliographic management software.

Can I use it from off campus?
Yes. Connect via the proxied link and enter your UT EID and password when prompted. Access is restricted to current UT Austin students, faculty and staff.

What structure editors are supported?
Reaxys offers MarvinSketch and other internal editors that don't require plugins, but which require current Java and JRE. There are other Windows editors that require plugins: these can be downloaded from the Reaxys site. You can choose your favorite in the My Settings tab. You can also copy structures from ChemDraw and paste them into the editor.

The structure editor won't open.
This is most likely a Java problem. Make sure Java and cookies are enabled in your browser. Check your Java and/or JRE versions and update them if necessary. Try a different browser. It varies from machine to machine. Consult the About Reaxys page for compatibility and version details.

Should I search in SciFinder or Reaxys?
Use both, especially when trying to determine if a specific molecule has been reported. SciFinder and Reaxys are complementary resources, and although both are ultimately based on the primary literature, they are quite different in the ways they scan and index the literature, the ways they register compounds and index reactions, and in the time periods they cover.

Reaxys is valuable for obtaining preparation/reaction methods and physico-chemical data for pure compounds, and especially for its thorough coverage of pre-1960 organic literature. Since its modern journal coverage is much more selective than SciFinder's, search results are usually more manageable.

SciFinder excels with its wider coverage of literature and patents from ca. 1965 forward, its comprehensive registration of all types of chemical compounds, polymers, and mixtures, and its more thorough coverage of organic reactions after 1985. CAS also scans more source publications, indexes new material more rapidly, and is updated daily. Results can be voluminous because of the sheer number of references (>40 million), so it's important to do focused searches and use the refining and analysis tools.

Is there any reason to consult the printed Beilstein or Gmelin handbooks anymore?
The Reaxys database does not duplicate the Handbooks. Pertinent data and references were extracted from the printed works to create the retrospective portion of the electronic database.

The printed Beilstein Handbook entries, while in highly abbreviated German, provided some textual descriptions of synthetic chemistry that are not reflected in the online version. Beilstein Supplement V (Heterocyclics, 1960-79) has only been partially converted. Conversely, there is much information later added to the Beilstein database that was never included in the printed Handbook.

Numeric data from the print Gmelin Handbook up to 1975 is mostly in Reaxys. Handbook data from 1976 to 1998 (when it ceased) have not been added. Print Gmelin remains useful because it was more textual and narrative in presentation and provided useful tables and graphs that are not included in Reaxys. It is a good idea to follow up a database search with a look in the corresponding Gmelin volumes.

Because the print and online formats are complementary, the printed Handbooks remain available in the Chemistry Library.

What documentation is available?
Reaxys' own training materials and help pages are a good place to start. They offer video tutorials, recorded webinars, and PDF quick guides. There are also various useful academic guides such as Michigan's. Technical specs are available at the Reaxys Training & Support site.


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