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Chemistry Forums for Students => Organic Chemistry Forum => Organic Spectroscopy => Topic started by: ao.sora on October 11, 2016, 05:02:12 AM

Title: Need help with IR spectroscopy question
Post by: ao.sora on October 11, 2016, 05:02:12 AM
Can you help me figure out the functional groups in the attached spectra?

Thanks!!
Title: Re: Need help with IR spectroscopy question
Post by: Arkcon on October 11, 2016, 06:10:47 AM
I'd like to welcome you, ao.sora: to the chemical forums, but I'd like to remind you to read the Forum Rules{click} (http://www.chemicalforums.com/index.php?topic=65859.0).  You agreed to read and follow them when you signed up, and they apply to everyone, we'd like to see your attempt first.

One of the biggest problems here on the chemical forums is "helping" someone with something that they can simply look up in a reference.  We can't help you read, or check a table from a distance, you either do it, or you don't, and we do it for you, or we don't.  So start with the highlighted peaks, check a table, and tell us what's clear, and what's not.
Title: Re: Need help with IR spectroscopy question
Post by: Babcock_Hall on October 11, 2016, 11:23:09 AM
@OP, What does the signal near 1740 wavenumbers suggest to you?
Title: Re: Need help with IR spectroscopy question
Post by: ao.sora on October 11, 2016, 06:58:09 PM
Carbonyl functional group..i do recognize that but I am confused about the peak at ~3500cm-1...
Title: Re: Need help with IR spectroscopy question
Post by: Babcock_Hall on October 11, 2016, 08:44:22 PM
Carbonyl sounds reasonable.  The signal at 3500 cm-1 could be a second functional group.  What does its position and breadth suggest to you?
Title: Re: Need help with IR spectroscopy question
Post by: ao.sora on October 12, 2016, 02:01:32 AM
secondary amine fits but there are no amines in the list of molecules given to me
Title: Re: Need help with IR spectroscopy question
Post by: Babcock_Hall on October 12, 2016, 09:20:46 AM
Secondary amines are usually not that broad.  What else has a stretch in that region?
Title: Re: Need help with IR spectroscopy question
Post by: ao.sora on October 12, 2016, 02:04:10 PM
Alcohols but then carbonyl is present
Title: Re: Need help with IR spectroscopy question
Post by: Babcock_Hall on October 12, 2016, 02:46:36 PM
Do you know for certain that there is only one functional group?  If so, is there any functional group that combines the elements you have identified?