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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: lch988 on January 23, 2008, 08:47:53 PM

Title: FT-IR Peaks at 2635cm-1 and 2340cm-1
Post by: lch988 on January 23, 2008, 08:47:53 PM

Hi,

I have a FT-IR spectrum that shows peaks (rather broad) at 2635 and 2340cm-1. In addition, the spectrum also shows a broad hydrogen-bond-network peak at 3100 - 3600cm-1.

Elemental analysis reveals the present of NITROGEN.

I tried many databases but there isnt any info on 2635 and 2340 peaks. Wonder if anyone has clues with this?

Your help is very much appreciated!

Title: Re: FT-IR Peaks at 2635cm-1 and 2340cm-1
Post by: agrobert on January 23, 2008, 09:13:27 PM

How familiar are you with IR?

http://en.wikipedia.org/wiki/Infrared_spectroscopy

http://en.wikipedia.org/wiki/Infrared_spectroscopy_correlation_table

http://organicworldwide.net/infrared/

http://infrared.als.lbl.gov/IRbands.html

The peak around 2300 cm^-1 is typical for a nitrile stretch (C=N) or it could be that you didn't run a background scan and CO₂ is showing up.  Not so sure about 2600 cm^-1 but you should be more descriptive of your peak size and characteristics. 

Don't depend on these tables.  Understanding IR and predicting/assigning stretches takes practice and experience.