Spectra and Spectral Data

Finding spectral information for a compound of interest often requires you to search the chemical literature, since only a tiny fraction of known compounds can be found in online spectral databases or printed compilations. Spectral data reported in journals are usually brief (peaks, solvent) and intended to characterize a synthesized compound; graphical spectra are rarely shown.  In some cases the spectral data are provided in an article's Supporting Information (SI).

There are several ways to search SciFinder-n for specific data.

• If you are looking for a spectrum of a specific substance, the best starting point is to do a Substance search using a CAS Registry number (if you know it), a name, or draw/paste its exact structure.  From the substance record, click Get References, then limit the retrieval to Spectral Properties. You can then refine these results by topic keywords such as "uv" or "emission" to narrow down to a particular technique/type, although this is somewhat imprecise. Two major caveats about the Spectral Properties role:
  • The Spectral Properties role has only been assigned to RNs in documents from 1967-forward.
  • It  is only assigned to a RN when those properties are a primary topic of the reference, not when those properties are reported in passing.**
  • For pre-1967 references, search by substance, get All References, then Refine the results using keyword(s) in the Research Topic option. This is less precise, but the only way to include earlier papers.
• You can also start with a Reference search, and enter a text query using a CAS Registry Number: e.g. "emission spectrum" AND 12345-67-8. This works best if you already have the substance RN, but you can otherwise use a chemical name, which is less precise.
• ** Note: CAS indexing policy generally omits mention of spectral information that may be present in an article, unless it is the document's primary focus. Spectral information that is reported incidentally, or as part of the routine characterization of a synthesized compound, is generally not indicated in the CAPLUS record's indexing terms or abstract. Only articles that provide significant spectroscopic detail about a compound will have the "Spectral Properties" role assigned to the compound's Registry number. In this regard, Reaxys is the more detailed indexing source, so it is important to check both when searching the literature for spectral data.