Note that this database requires registration (see above.) If you are logging in from off-campus, either use the campus VPN or the Library proxy server. If you use the links in the Library databases lists, our systems will automatically detect whether you are on-campus, already connected to the proxy or VPN, or off-campus and unconnected. If the latter, you will be automatically routed to a proxy server login screen. Once logged in, you will continue on to the SciFinder login page.
Enter your username or the e-mail address you used to register. A "Next" button will appear. Click it. On the next screen, enter your password, then click "Log in". Do NOT select :Keep me logged in" if you are using a public workstation.The system will remember your username/e-mail for future use unless someone else logs in on that workstation.
Note that the default opening screen is set for substance searching. If you have previously searched in this account, your recent search history will display below the search window.
In the upper left is the CAS SciFinder-n logo. T
On the left are three vertically-arranged dots. Clicking on them opens a drop-down menu:
This enables the user to switch freely among CAS products. Note that you or your institution must subscribe to the product in question to access it, and at the moment, UCSB only subscribes to SciFinder-n.
In the upper right are three options:
To the left of the screen is the menu for selecting which type of search you wish to do. By default, the highlighted choice will be whichever type of search you did last.
To the right of the Search Selection menu is the Search Window, which will vary by the type of search selected.. For searches involving substances or reactions, the window will include both a search term window, and a Draw icon to open the structure drawing tool (discussed in detail in Lecture 14). All search windows will have the magnifying class icon. Click on it to begin the search.
Below the search window is a drop-down menu for searching specific fields appropriate to the type of search you are conducting.. The "Add Advanced Search field" link lets you add additional fielded searches to combine with your basic search.
CAS Registry Numbers were first assigned to substances by Chemical Abstracts Service in the 1960s when they created a computerized database of substances to aid their indexers in determining whether a substance in a document they were indexing had previously appeared in the literature. CAS RNs are of the form: xxx-xx-x where the first number is 2-7 digits long, the second number is always two digits long and the third number is a check digit generated by an algorithm from the previous digits in such a way that most common mistakes in entering an RN would generate an invalid RN, rather than the RN for the wrong substance.
Every unique chemical substance gets its own RN, including stereoisomers, isotopically-labeled substances, mixtures, etc. One exception to this is that polymers which only differ in chain length or molecular weight do not get different RNs, nor do plastics which differ only in how they were processed. This is a long-standing CAS indexing policy, somewhat to the regret of scientists working in the plastics industry.
Note that CAS RNs are purely identification numbers, and do not convey any information about the structure or properties of the substances they represent. Most RNs are assigned by indexers in the course of indexing documents. Some are assigned at the request of chemical manufacturers or government agencies, and represent substances which have no published references. Note, too, that CAS RNs are the property of Chemical Abstracts Service and are not in the public domain. Reaction to this led to the creation of the InChI system (International Chemical Identifier) as an alternative which would be freely available to anyone.
Below is the substance detail for aspirin
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Second left-hand vertical tool bar:
Verticle Bars on the right-hand side of the drawing window
With the tools above, drawing structures in SciFinder-n is relatively straightforward. SciFinder automatically checks for "normalized" bonds in aromatic structures or tautomers.
Some general tips -- While you can do most functions in any order, I prefer to do the following:
As an example, let's take a look step-by-step at the drawing of the structure of feropolone (Note: the screenshots below were made with the Java structure editor, but the process is the same with the non-Java editor):
First, use the ring drawing tools (right-hand tool bar) below the drawing board to draw in the ring portions of the structure -- the benzene ring tool for the six benzene rings :Note that the precise positioning is not important - I've laid them out similar to the final 2-D structure for convenience.
Now, use the Pencil tool to draw bonds connecting pairs of benzene rings to create three biphenyls. Note that as the Pencil tool touches an existing atom or bond, that atom or bond is highlighted. Hold the mouse putton and go to the corresponding atom on the adjacent ring. As you do so, a bond will appear. When you reach the other atom, the bond will link the two rings.
Continuing with the pencil tool, select N from the list of common elements on the right-hand tool bar and change one carbon on each ring in the ortho position to the biphenyl bond to a nitrogen. Now, you have three 2,2'-bipyridyls.
Now, we can use the Atom button,(the periodic table icon on the left-hand tool bar) to open the periodic table and select Ru and close the periodic table. Note how the window to the left of the buttons now shows a Ru. That is the current atom that will appear when you draw. Now, move the pencil tool cursor to the center of the circle of bipyridyls and click to place a ruthenium atom there.
Now use the pencil tool to connect the Ru atom to each of the six nitrogens, one at a time. Now, your structure is drawn. You could use the + tool in the left-hand menu bar to add a +2 charge to the Ru, but charge assignments are not used in searching by SciFinder-n.
Now, click OK to return to the search screen.
Note how the structure Edit icon is now highlighted. Click the Search icon to carry out the sturure search. You can ad additional substance search terms (keywords, property values, etc.) before launching the search.
When you click the Search button, you gett a display of thesbustance answers in the SciFinder-n database that match your query. The default sort order is Relevance though you can select other sort orders. Note, too, on the left, that there are three answer sets created by your search:
"Filters" allows you to limit your search results to certain types of substances or to exclude certain types of substances. Note that you can apply multiple filters to the same answer set. Filters can be removed as well.
The previous tab, "Substance Searching", lists the various filters available for substance answer sets. Note that a filter category only appears if it is applicable to the answer set in question. If the number of possibilities in a given option is small, they will be listed in order of descending occurrence. If they are larger, you'll see a "View All" link, which will open a table of all the possibilites. For esample, here's the table of Reference Roles for the Ru*bipy)3 answer set above:
Note that the roles can be lised either in descending order by occurrence cunt, or alphanumberically. If you select more than one option from the table, they are, in effect "OR"ed together. If you want to "AND" roles together, apply them one at a time.
Structure Search Within Results -- Why, you might ask, would I want to refine one structure search with a second structure search? Why not just do the structure search you wanted in the beginning. The answer is that some types of structure search are too general to run on the full database. But if you can create a smaller subset of substances to run your desired structure against, you can be successful. The subset can be created by either structure or molecular formula searching, or by using the Get Substances option on a document answer set. Also, by starting with a more general search, you can filter for a particular structure option, then back up and try a different option.
© 2023 Charles F. Huber
This work by Charles F. Huber is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
Based on a work at guides.library.ucsb.edu
Screenshots of Reaxys are copyright © 2023 by Chemical Abstracts Service (CAS), a division of the American Chemical Society, and are used for fair use educational purposes only