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1H NMR Spectrum Interpretation

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I need to: provide an interpretation for all protons in the 1H NMR spectrum of 4-vinylbenzoic acid and indicate how the 1H NMR spectrum of the corresponding methyl ester would differ from that of the acid.

On the 1H spectrum, I see a quartet around 6.8ppm which I don't know where it comes from, because I think it should be a triplet and also why there is two doublets, when I think there should only be one. I can see that the singlet at 7.2ppm is probably the H of -OH. and the two doublets at around 7.5 and 8.0ppm are Ar-H protons. I also need help on the methyl ester part.

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4-Vinylbenzoic acid is an aromatic carboxyllic acid. There are three distinct groups in this molecule: benzene ring, vinyl group and -COOH group. In all there should be 6 NMR peaks .2 peaks corresponding to Ar-H, 3 peaks due to the vinyl group and one peak due to -COOH group. You are getting exactly what is expected. The peak at ...

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