#IR SPECTRUM PEAKS CHART HOW TO#

Step 5: Is there any tongue like peak? Observe it. If small peak around 3300 cm -1 is present then thats the peak due to Sp C-H bond( in alkyne).If small signal peak is present around 3000-3100 cm -1, then we can say thats the peak due to Sp 2 C-H bond( in vinylic C-H bond).If single small peak is present around 2800-3000 cm -1, we can say thats the peak due to sp 3 C-H bond( in alkane).The borderline 3000 cm -1 contains small peak above or below it. Step 4: Draw a line at 3000cm -1 and observe signal above and below it If you observe any peak in the range of 2100-2300 cm -1 then the compound has triple bonds such as C≡C(2100-2200 cm -1) and C≡N (2200-2300 cm -1). Step 3: Look at triple bond region(2100-2300 cm -1) Therefore, we will try to identify the spectra by observing the diagnostic regions. Step 1: Look at the diagnostic region first(above 1500 cm -1)Īs we know, the fingerprint region is very complex, it is difficult to read or identify. Are you ready for the trick? Ok, let’s move to some easy tricks to identify the spectra. But we will try to identify the peak by observing the shape of the peak and the location of that peak in the spectra. Now, remember these values of absorption frequency. Therefore, two identical compounds have exactly overlapping spectrum. Note: Two or more compounds may have the same diagnostic region but different fingerprint regions. Before going to these regions, let’s study the absorption frequency of each bond or functional group. By observing these we can identify which types of bond or functional group is present. But diagnostic regions have some characteristic regions. The fingerprint region is unique for each and every compounds just like the fingerprint of humans. The fingerprint region ranges from 400 to 1500 cm -1 and the diagnostic region ranges from 1500 to 4000 cm -1. Do you know, how many regions are there in IR spectra? Actually, there are two regions: fingerprint region and diagnostic region. If you don’t know about the basics of IR spectroscopy, you can read.īefore discussing the basic idea to analyze the IR spectra, we must know about the regions present in the spectra.

#IR SPECTRUM PEAKS CHART HOW TO#

How to read IR spectra? Everybody has to face some difficulty while analyzing due to a lack of basic ways or tricks.

Ir spectrum peaks chart