Vlad's+Analysis+of+the+H-NMR+of+Glutamine

By Vlad Limonnik

Figure A- Glutamine

Figure 1.1- H-NMR Spectrum of Glutamine

Figure 1.2- scale in ppm (delta scale), relative to tetramethylsilane (TMS), defined as zero ppm

Figure 1.3- One sharp peak at ~4.807 ppm is seen because of the solvent used. The chemical shift of N-H and O-H protons depend on the concentration and the solvent so it is often difficult to tell whether or not a given peak corresponds to one of these types of protons. Deuterium oxide, D2O, was used and caused the large peak between 4.800-4.815 ppm. By using D2O, NH2 and OH groups will not be visible in the spectrum.

Figure 1.4- This shows a triplet at ~3.78, ~3.76, and ~3.74 ppm. This corresponds to the H atom bounded to the carbon that is directly connected to the amine (NH2) and the carboxyl (COOH). The peaks are in a ratio of 1:2:1

Figure 1.5- This figure shows a doublet of triplets, ranging from ~2.420 and ~2.470 ppm. This corresponds to the CH2 that is located in between the carbon that is connected to the amide, and the carbon that is connected to a carboxylic and amine group. The H's from the CH2 group couple with the two H's on the carbon connected to an amide, and couple with the one H that is connected to the carbon that is connected to a carboxylic and amine group.

Figure 1.6- This figure shows a triplet at ~2.150, ~2.140, and ~2.120 ppm. These peaks correspond to the CH2 group that is directly connected to the amide. The two peaks at ~2.110 and ~2.100 ppm are probably due to contamination of the sample.

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