Using 4-ethylbenzene derivatives to examine coupling constants, signal resolution and deuterium exchange in proton NMR spectra | Poster Board #140

The ¹H NMR spectra of a series of 4-Ethylbenzene derivatives have been used to create in-class activities designed to introduce students to the concepts of spin systems and coupling constants, signal resolution issues in spectra, and deuterium exchange.
The ¹H NMR spectra of 4-ethylbenzene derivatives feature coupling arising from distinct spin systems. Since the resonances of these spin systems occur in well-separated regions, these spectra are useful examples with which to introduce students to the concept of coupling constants in ¹H NMR. Furthermore, the different 4-ethylbenzene derivatives give rise to spectra with different degrees of resolution between the resonances of the two chemically distinct hydrogen positions on the benzene ring. Finally, by comparing the spectra of 4-ethylaniline, 4-ethylphenol, 4-ethylthiophenol and 4-ethyltoluene before and after the addition of D₂O, students can determine which hydrogen atoms in these molecules can participate in deuterium exchange.
In our poster, we will present our activities, which include the ¹H NMR spectra of the compounds collected using a 60 MHz NMR spectrometer together with a series of questions designed to guide students through their analysis.