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Homework Help: 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

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  2. jcsd
  3. Jan 19, 2017 #2


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    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.
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