Can someone help me identify this molecule with IR

I need to identify bands A through L.

Here is the IR spectra: http://xs.to/storage/anonym/2011/08/22/102601.jpeg

So far I have this:


A – Arene @ 3030 or Alkene @ 3020-3100
B - Alkane 2850-3000
C – C=C Alkene @ 1950 or
D - @ 1850
E - @ 1800 – C=O Acyl Halide
F - @ 1710/1720 – C=O Ketone or C=O Carboxylic Acid
G - @ 1600
H - @ 1500
I - @ 1450
J - @ 1370

Could someone please help me out? Getting quite confused with this. Thanks!

You have an aromatic ring, and the bands C,D,E,F will give you the substitution pattern. And it really tells me it is a mono-substituted aromatic compound.

You can't have a carboxylic acid, since there is no broad peak around the area of A. You need to look at reference spectra for alcohols and acids to see the broad peaks which are very diagnostic.

New beginners always want to over interpret an IR spectrum. So for the time being forget about those bands H and higher. They can help confirm your decision, but don't use them to make your decision.

G will tell you what carbonyl group you will have. It is probably an aromatic aldehyde.

It really is not too bad for benzaldehyde, but this is where those other bands can help you further pin down a structure.

1500 and below is known as the fingerprint region, it is extremely difficult to associate any peaks in that range with a particular bond. It is often ignored.

Here is a copy of a data sheet which contains all the values you need

http://www.megafileupload.com/en/file/32…