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Searching SciFinder

SciFinder: A CAS Solution

Exploring Substances

Searching for a Substance by Chemical Structure

Chemical structure uses a structure query to retrieve substances of interest. You can specify an exact structure, a substructure, or a similarity structure.

  •  Under the Substances list on the left-hand menu, choose "Chemical Structure"

  •  Open a new pop-up window by clicking on the stricture editor

  • Using the drawing tools create the structure you are interested in

Example of drawing using tools


  • It is possible to search for an exact match, substructure search or similarity search. Once you select the type of search, hit "OK" and will appear in the search box, You have to hit "search" even after selecting "OK"

  • Go to Refining Results for substance searchs

Searching by Substance by MARKUSH

Markush searching retrieves patent references by matching your structure query against generic structures referenced in patents. Markush structures (-R) are chemical symbols used to indicate a collection of chemicals with similar structures. They are also known as "generic" chemical structures. The Marush Structures are used to protect whole classes of compounds with common properties. 

Example of drawing using tools

  • R= must equal 2 or more element and less than 20 possible elements

  • It is possible to search for only the variables specified, or for a wider range to look for anything search for the substructure

  • Refine the results using the same approach as with reference searching. 

Searching by Substance by Molecular Formula

Molecular formula retrieves substances whose formulas contain the specified atoms and atom count.

Molecular Formula - Use Hill Order to type in the molecular formula

Hill Order

  • All like atoms are grouped together

  • Carbons first, then hydrogens, and everything else in alphabetical order

  • In the absence of carbon, all atom groups should be in alphabetical order.

  • The formula search is case sensitive and can distinguish Co from CO

Screenshot of search using molecular formula

Hit "Search" to retrieve the results

Use the menus on the left side to analyze and refine the results

It is possible to analyze by: 

  • Bioactive Indicators

  • Commercial Availability

  • Elements

  • Reaction Availability

  • Substance role

  • Target Indicators 

Screenshot of search

Go to Refining Results for substance searchs

Searching by Substance by Properties

Property allows you to begin a search with a set of substances that meet specific property criteria

Properties have two categories; Experimental and Predicted.

  • Experimental properties include; bioconcentration factor, boiling point, density, enthalpy of vaporization, flash point, freely rotatable bonds, H donor/acceptor sum, KOC, logD, logP, mass intrinsic solubility, mass solubility, Molar Volume, Molecular Weight, pKa, Polar surface area, Vapor pressure. 
  • Predicted properties can be the: boiling point, density, electric conductivity, electric conductance, electric resistance, electric resistivity, glass transition temp., magnetic moment, median lethal dose, melting point, optical rotatory power, refraction index, or tensile strength.  
  • Go to Refining Results for substance searches

Screenshot of search by property





The University of Pennsylvania subscribes to other resources which have greater flexibility when searching by property


Searching by Substance by Substance Identifier

Screenshot of substance identifier searchSubstance Identifier is the most open ended of the search options. A substance identifier can be a CAS registry number, or chemical name, a common name, trade name, or acronym, the search can have up to 25 substance identifiers, and should be entered one per line.

From the results SciFinder retrieves the substance to see additional information about a substance, use the icons and links that appear around the structure.

  • References (the paper icon)

  • Reactions (the green beaker icon)

  • Commercial sources (the orange flask with price tag icon)

  • Links to Regulatory Information, Spectra and Experimental Properties, are in the bottom left corner when the data is available

  • Click the CAS Registry NumberSM to learn even more about a particular substance.

Screenshot of search results

Refining Results

Once you have run the initial search it is possible to refine the results using the structure editor using the menu on the left side of the searching page.

  • Chemical structure- The structure editor allows the user to search via structure, which is a unique refinement tool or if the structure is; 

    • commercially available

    • single component

    • specific substance classes

    • specific types of studies.   

screenshot of structure editor

  • Isotope containing

    • Include only isotope-containing substances 

    • Exclude isotope-containing substances

  • Metal containing

    • Include only metal containing substances 

    • Exclude metal containing substances

  • Commercial availability or not

  • Property availability

    • any property

    • any predicted property

    • any experimental property

    • any selected experimental property

  • Property values​

    • (Boiling Point, Melting Point, Predicted H Acceptors, H Donors, Molecular Weight, logP, Freely Rotatable Bonds, Bioconcentration Factor, Density, Enthalpy of Vaporization, Flash Point, H Acceptor/Donor Sum, Koc logD, Mass Intrinsic Solubility, Mass Solubility)

  • Reference attachment


Training video from CAS

Need to know Structure Searching

A link to the CAS with helpful training videos and demonstrations for reference searching in Scifinder.


Screen shots throughout this guide are taken from SciFinder and are used with permission from CAS. Copyright 2020 American Chemical Society, all rights reserved.

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