Question

What structural information does infrared (IR) spectroscopy give? And what does NMR spectroscopy say about a compound's structure?
Why is IR alone not sufficient to determine an unknown compound? Why is NMR required?

(Organic Chemistry)

Answer 1

IR will give only informaton about functional groups. For structure determination we need lot information.

If you have NMR in your hand you can see the enviornment of protons. it is methyl or ethyl or phenyl or oxygen attached or nitrogen attached. By integration you can get no of protons. By coupling constant and splitting pattern you will enviornment of protons. Overall by nmr you will come to know the structure.

All data present like proton NMR , C13 NMR, Mass and IR we can easily determine the structure of compound.