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SciFinder is an entry to research from many scientific disciplines including biomedical sciences, chemistry, biochemistry, engineering, materials science, agricultural science, and more.

Explore Substances - Searching Functionality


You may search for substances using any of the following queries:

  • chemical structure, either as
  • Markush structure (matches stucture query against generic structures included in a patent);
  • molecular formula (matches on exact atom symbols and atom counts);
  • a particular physical property (experimental or predicted); or
  • substance identifier (i.e., CAS registry number or complete chemical name, common name, trade name, or acronym).  NOTE:  By far, the easiest search is when you know the CAS Registry number for a substance! 

Each of the links above will explain in detail the best practices for executing each type of query as well as provide definitions for specific variables that may be searched.  You must be logged into SciFinder® for these links to work.

A search for substances using either chemical structure or Markush structure requires that you use the Structure Editor to recreate the structure of the substance.  When you choose to search by chemical structure, you have the option of immediately refining your search (see "Advanced Search" :

  • the characteristics of the substances to be retrieved (i.e., whether the structure as a single component, whether the subtance is commercially available, and whether it is included in any references).
  • the class of substance (i.e., alloy, coordination compound, incompletely defined, mixture, polymer, or "organics, and others not listed").
  • the type of study done on the substance (i.e., analytical, biological, preparation, reactant or reagent).

Depending on the specificity of the structure search being done, you may also be prompted for additional ways of limiting the search, such as "formula weight".

My advice, especially if you are not sure what to expect in the way of results or are not looking for something specific, is to do any refinements to your query AFTER you have retrieved your first results list.  That is, move from the general to the specific in your searching.

Tips for Exploring Substances

Chemical name may seem like an easy and straightforward way to search for a substance but Judith Currano, Chemisty Librarian at the University of Pennsylvania (2014, p110), notes that there many different names that a substance can go by:

  • systematic names assigned by IUPAC or CAS
  • common names
  • historic names
  • trade names
  • brand names

She observes that any name you enter must be found in that substance's record and advises that you may have to enter several different synonyms to match what you are looking for.

Currano also points out that formula searching presents an opposite sort of problem, in that a single formula may represent the composition of many different substances, a problem especially evident when seraching for common organic substances.  You will have to review several hits to locate the substance of interest or limit your search with additional information to narrow down the possibilities (2014, p111).

Using substance identifier numbers such as the CAS Registry number or the InChI number are additional tools to search by, although these are not without their issues as well.  The CAS Registry number assigned by Chemical Abstracts Services is a unique identifier but the problem is knowing the CAS Registry number assigned to your substance of interest!  InChI (International Chemical Identifier) numbers were started in 2000 by the International Union of Pure and Applied Chemistry (IUPAC).  InChI numbers are unique and non-proprietary (individuals can create them using InChI generators (e.g., but they are complicated to write so they used infrequently for searching (Currano, 2014, p111-112).

Currano points out that a substance's chemical structure is also unique but they can be cumbersome to draw, especially if the structure is large and that success searching by structure is contingent on how the structure is represented in the literature; structure searching relies on matching the connections between atoms in a structure as drawn with the connection tables for substances in the database.  Where those match determines the substances returned as results.


Currano, J. (2014).  Searching by structure and substructure.  In J.N.Currano & D.L. Roth (Eds.), Chemical Information for Chemists: A primer (pp.109-145). Cambridge,UK: RSC Publishing.


Limiting your Substance Search Results

As noted above, you may choose to limit your search at the point of entering your query by dropping down the advanced search menu.  Alternatively, you can refine your search once you have retrieved your list of references.  SciFinder® offers two ways to do this when exploring substances:

1. Analyze: allows you to explore just a subset of the results returned (e.g., in the illustration below, one could look at the 102 results categorized as an "analytical study" by clicking on that bar) OR it allows you to analyze the results according to some other criteria:  bioactivity indicators, commercial availability, elements, reaction availability, substance role (the default), or target indicators.

2.  Refine: allows you to further limit the results by different characteristics of the substance, revise the structure drawing, or retrieve only those results that conform to some expectation (e.g., references, commercial availability, etc.



Tutorial:  Introduction to Substance Searching.  (~20 minutes)  You must be logged into SciFinder for this link to work.