Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

What is the finger print region of an IR spectrum?

  1. Feb 21, 2012 #1
    i was just wondering what is considered to be the finger print region in an IR spectrum. Is there a range of wavenumbers which are designated as the finger print region?

    ...let me clarify um so a C-O bond in an ether (and maybe alcohol) is suppose to have a peak in the 1000-1200cm^-1 region and i also know that many other functional groups absorb in this region as well.

    and i just did a question where I looked at an IR spectrum and based on everything decided that it contained an ether, aldehyde and a secondary amine. however the solution says the molecule is an aldehyde.

    it explained that the part i thought was an amine as just an impurity from water or a hydrate, but it didn't explain the ether peaks at 1000-1200cm-1. is that because anything before 1500cm-1 is considered the fingerprint region? or is the peak suppose to look different like in that region for it to be an ether like broad or something (like in O-H stretch in alcohols or carboxylic acids) or am i just looking too much into it, since this is organic chem 1

    below is a picture of the IR spectrum I was looking at

    thank you:)
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Jan 19, 2017 #2


    User Avatar
    Science Advisor
    Gold Member

    Typically anything under 1000 cm-1 is considered to be the fingerprint region, but sometimes the region of the spectrum you were looking at (which you thought was an ether) can include a lot of alkyl bends and wags as well.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?