Mrugesh+Patel's+HNMR+for+2-aminoacetic+acid





Figure 1 above represents the HNMR for 2-aminoacetic acid (more commonly known as Glycine). Clearly there are two major peaks shown which represent the different types of Hydrogen’s present within the molecule. There is also a very small peak at 0 ppm, which represents the standard used (TMS). A close-up of the two major peaks is necessary to ensure that there are no doublets or multiplets.



In Figure 2, a close up of the peaks in Figure 1, it can be seen that the first peak occurs 3.55 ppm and the second occurs at 4.81 ppm. The first peak, occurring at 3.55, is as expected for the Hydrogen molecules on the Nitrogen. Each pair of H’s, on both the Nitrogen and the Carbon attached to the Nitrogen, are both the same since they lie in the same ‘chemical environment’. As a result, there are only singlet peaks present on the HNMR plot. As for the other peak at 4.81 ppm, it occurs due to the H on the hydroxyl group present on the other end of the compound. The H which is present on the ‘OH’ is expected to have a peak around 4.5 ppm, but is slightly deviated due to the C=O group which is present right next to it. Additionally, notice that combining the OH with the C=O gives a carboxylic acid group which is supposed to be indicated around 10-12 ppm. This is not shown by the HNMR spectrum. This can be due to the fact that the last data point on the plot occurs at about 10.8 ppm and the data needs to be carried out further to actually detect the carboxylic acid peak.