# H NMR of 4-chlorochalcone

In an aldol condensation reaction, I synthesized a molecule out of two unknown reactants. These reactants I found to be 4-chlorobenzaldehyde and acetophenone which made 4-chlorochalcone. I was given an H NMR spectrum to identify and label the hydrogens for the molecule but am having trouble reading it!

There is a quintuplet with an integration of 6 but no where in the molecule am I seeing 6 hydrogens that share a chemical environment (I counted 7 environments). Is this possible or could I have come up with the wrong product structure?

Any help deciphering this would be great!

• The region corresponding to 6 hydrogens doesn't have to be 6 equivalent hydrogens. It could be 6 hydrogens that are in a similar chemical environment. So that could be two different hydrogen types in a 1:5 ratio, or a 2:4 ratio, or a 3:3 ratio. Or it could be three hydrogen types in a 1:1:4, or a 1:2:3 ratio, or a 2:2:2 ratio. And so forth up to six hydrogen types in a 1:1:1:1:1:1 ratio. – jerepierre Mar 29 '16 at 21:42
• Based on the structure, you have already determined correctly that there are 7 hydrogen types (environments). How many of each type do you expect? What multiplicity do you expect for each? What chemical shift makes the most sense for each environment? Assign the peaks as best you can for your prediction, and whatever is left is likely in that multiplet with integration 6. – jerepierre Mar 29 '16 at 21:43
• Interesting... But I don't see 6 similar hydrogens. I see 5 hydrogens on the phenyl on the left that could be similar. But where is the sixth? I'll try assigning them and see where it gets me! Thank you! – Salma Mar 29 '16 at 21:47
• The integrals in a quintuplett should be 1:4:6:4:1. Pascals triangle. Not here. The dubletts at 7.4 and 7.77 both look suspiciously like they are part of an AB coupling each. – Karl Mar 29 '16 at 23:55
• Could it possibly be an overlapping doublet triplet doublet? What would that mean for the structure? – Salma Mar 30 '16 at 14:22