STN International - The Scientific and Technical Information Network
Search Example: Chemical Formula Search
Question: Molecular formulaHow can I find papers discussing the substance with this structure:
Strategy: Locating chemical substance information using a chemical formula
is a 2-step prozess:
1. Locate the CAS REGISTRY record for the substance by using the CAS Number option.
2. Select the link to substance information of interest ("crossover search").
Use this strategy as well when you want to find chemical substance information and you know the molecular formula.
Search Strategy
Please click on the small screenshots to get larger ones. The large screenshots themselves can also be closed by clicking.
Log on to STN Easy at STN Easy Home Page
If you do not have an existing STN account:
To open a new STN Easy account, click the blue "Open New Account" button on the STN Easy Home Page and complete and submit the online forms. Within 30 minutes, your STN login ID and password will be sent to the e-mail address you specify.
If you have an existing STN account:
To log on to STN Easy, simply enter your login ID and password.
Then click "Start Your Session."
  More info about STN Easy Home Page
   Select Search Mode:
STN Easy Search Page
The Search Page is displayed. It offers three different search options: "Easy", "Advanced" and "CAS Number" Search.
Start by selecting the "Advanced Search" tab.
The Advanced Search option prompts you to choose the category of databases you wish to search. Click the blue "Select Your Category" button for the list of categories available.
  More info about STN Easy Search Page
   Select Databases:
Select database category
An additional browser window is opened. It displays the list of STN Easy database categories.
Click the "Chemical Substances" category to select it.
The window closes and the name of the category you selected is displayed next to the "Select Your Category" button. - You are ready to enter the search terms.
Helpful HINT: To list the databases included in the category simply click the yellow Database Folder icon to the left of the category name. Furthermore, if you do not want to search a particular database, just deselect its corresponding check-box.
More info about databases
   Enter Search Terms:
Enter search terms
The "Chemical Substances" Search Page features 5 different search-fields in a drop-down menu: Accession No., CAS Number, Chemical Name, Molecular Formula and Word(s).
To find substance information using a chemical formula select the search-field "Molecular Formula".
Type the formula in the associated entry box - in accordance with the Hill System Order.
Click the green "Search" button. - Note that the search costs are displayed below the Search button.
More info about Search Guidelines
Helpful HINT: Use the free "Browse Index" button before clicking "Search" to confirm that the molecular formula you entered is spelled correctly and is included in the database you have chosen - before you actually pay for the search.
Simply select the formula you wish to search from the "Browse Index" list, then click "Search".
More info about Browse Index feature
   1. Answer Page:
Refine your search at Answer Page
The list of answers is displayed in a table format on the Answer Page.
Your search question and total number of answers are shown at the top of the Answer Page as well.
Molecular formula searches often retrieve more than one match. To focus on matches with attributes of interest, click the "Refine Your Search" button.
There is no additional charge to refine your STN Easy search!
More info about STN Easy Answer Page
   Refine Page:
Refine your search
The Refine Page is displayed.
Add a chemical name fragment to narrow your search. Use chemical name fragments describing a unique attribute of the chemical substance!
From the drop-down menus in the Search Term area, select "AND" from the combining operators and "Words" from the search term descriptor. Type the name fragment in the associated entry box.
Click "Search". - Refining is free!
More info about Refining
   2. Answer Page:
Select titles at Answer Page
The Answer Page reappears.
Review the answer titles, and click on the substance hyperlink of interest. - The display costs are shown to the right of the answer.
More info about STN Easy Answer Page
   1. Display Page:
See detailed record at Display Page
The REGISTRY Display Page appears.
It includes the CAS Registry Number and also provides a wealth of additional information about the substance through hyperlinks to other STN databases e.g. patents, chemistry references, chemical catalogs, life science, toxicology and more.
Click a category name link to search for your substance in that database cluster. The search fee is displayed next to the link. - In STN International, this type of search is called a "crossover search".
To locate chemical substance information, click the "Chemical References" link. You may search for references without any restrictions otherwise you may narrow your search to one or multiple subjects of interest provided in the scrollable list e.g. preparation, purification, reactants and more.
Helpful HINT: Have a look at the 2-D or 3-D model which may be viewed currently with browsers that support JAVA. Dragging the mouse over the 3-D structure will rotate the model (not available in search example) - without any additional charge!
More info about STN Easy Display Page
   3. Answer Page:
Select titles at Answer Page
Once more, the Answer Page is displayed.
Select the answer of interest. In order to view records for several answers at once, simply check the boxes next to the appropriate answers and click the blue "Display Answers" button at the bottom of the page.
Helpful HINT: You may also change the "Display Format" and "Display Style" using the selection-boxes at the bottom of the title list.
   2. Display Page:
Use Full-Text Option at Display Page
The Display Page shows the record for the answer you selected.
To access the full text of this article, click on the green "Full Text Options" button that appears below the document record.
You are directly taken to the ChemPort Connection.
   Full Text:
Chemport Connection
Several options are provided at the ChemPort web site, some with no additional charge and some with additional charges. The options available to you are in bright color.
Subscribers of the journal can simply click "Subscribers view e-article" to read the full text free of additional charge. - And the full text is displayed, right at your desktop.
Non-Subscribers may select the "Delivery via e-mail, paper copy, fax copy" option, which is always available for an additional fee.
In order to start a new search, simply click the appropriate search option below the STN Easy Logo on the blue Navigation Frame and a new Search Page is displayed.
More info about STN Easy Full-Text Option
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