Commonly Asked Infrared Spectroscopy Values

Posted on November 14th, 2012

Students are constantly looking for the most important information to know when studying organic chemistry. This is especially important when it comes to those pesky IR values. There are so many to know!

Question: Which IR values do I need to know?

Answer: The short answer- all of them. However, when studying these, it is helpful to start with the most important ones. Memorize these first, then learn the other ones.

For IR (Infrared Spectroscopy):

1) Very strong peak around 1700 = carbonyl group

2) Broad peak above 3000 = OH group in carboxylic acids, but be careful this could also just be a regular OH group in any alcohol

3) Just below 3000 = hydrogen on an alkane

4) Just over 3000 = hydrogen on an alkene

5) Sharp peak at around 3300 = hydrogen on an alkyne

For more help learning Infrared Spectroscopy and Nuclear Magnetic Resonance Spectroscopy values check out the Infrared Spectroscopy and Nuclear Magnetic Resonance Spectroscopy Study Chart. To learn more about our program click here.