Question

assign major bands & мм see ска 4-bromomethhengo acid in CDC13 rep'd by 3760 recrest from EOA 6.5 60 Peak at 7.24 is residual CHCl, in CDCI. Acid proton not shown ca. 12 ppm. The overly strong CHCI, signal is a result of hydrogen deuterium exchange between the solvent and the carboxylic acid.

Answer 1

ANSWER:-

FIRST NMR SPECTRA OF 4-bromomethylbenzoic acid shows 4 signals in the nmr spectrum

Peak at 12.00 ppm is due to the acidic proton as mentioned above

Peak at 7.5 ppm due to 2 hydrogen is due to the benzene ring proton

Peak at 8.0ppm is due to the other 2 similar protons of benzene ring .

Peak at 4.5 ppm is due to the methyl CH₂ of ring.

SECOND NMR SPECTRA OF phosphonium bromide , phosphonium bromide has 3 aromatic ring in the structure ,one phosphorus and one allyl group in the structure ,

Peak at 5.6 ppm is due to the allyl ring protons

Peak at 7.6 ppm is doublet of doublet due to the benzene ring proton which is near to allyl group

All the peaks between 8.0 to 8.5 ppm is due to all three benzene ring protons.

Carbon 13 spectra shows that peak at 110 ppmand 120 ppm is due to the allyl carbons

Peak at 130 ppm to 140ppm is all due to the benzene ring carbons.

Peak at 170 ppm is due to the allyl carbon near to benzene ring