NMR Spectroscopy help, Alevel Chem

For each structure, predict the number of peaks in its low resolution nmr spectrum corresponding to the different types of proton and also the number of each different type of proton (e.g. CH3CH2OH has 3 peaks in ratio 3:2:1).

(a) CH3OH (b)CH3CH2CHO (c) CH3COCH3 (d) (CH3) 2CHOH

Reply 1

lizardlizard

Low resolution means you don't have to worry about splitting due to protons in adjacent environments (if you haven't learnt about that yet, not a problem here since we are ignoring it).

The most helpful thing you can do in this question is to start by drawing out each structure.

For (a) this would be

You then need to identify which protons are in different environments. Here there are only 2 environments: the 3 H bonded to the C and the 1 H bonded to the O. Each of these different environments leads to 1 peak on the NMR spectrum, and the number of hydrogens relates to the size of the peak.